diff --git a/src/ifcopenshell-python/ifcopenshell/api/pset/add_pset.py b/src/ifcopenshell-python/ifcopenshell/api/pset/add_pset.py
index 835bd83d75..d28fe9b16d 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/pset/add_pset.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/pset/add_pset.py
@@ -121,27 +121,36 @@ def add_pset(file: ifcopenshell.file, product: ifcopenshell.entity_instance, nam
         has_property_sets.append(pset)
         settings["product"].HasPropertySets = has_property_sets
         return pset
-    elif settings["product"].is_a("IfcMaterialDefinition"):
-        for definition in settings["product"].HasProperties or []:
-            if definition.Name == settings["name"]:
+    # in IFC2X3 IfcMaterialDefinition not yet existed
+    elif settings["product"].is_a("IfcMaterialDefinition") or settings["product"].is_a("IfcMaterial"):
+        if file.schema == "IFC2X3":
+            ifc_class = "IfcExtendedMaterialProperties"
+            definitions = (d for d in file.by_type("IfcMaterialProperties") if d.Material == settings["product"])
+        else:
+            ifc_class = "IfcMaterialProperties"
+            definitions = settings["product"].HasProperties
+        for definition in definitions:
+            # In IFC2X3 not all IfcMaterialProperties has Name
+            if getattr(definition, "Name") == settings["name"]:
                 return definition
 
         return file.create_entity(
-            "IfcMaterialProperties",
+            ifc_class,
             **{
                 "Name": settings["name"],
                 "Material": settings["product"],
             }
         )
     elif settings["product"].is_a("IfcProfileDef"):
-        for definition in settings["product"].HasProperties or []:
-            if definition.Name == settings["name"]:
-                return definition
+        # in IFC2X3 IfcProfileProperties doesn't have Name and we cannot identify them
+        if file.schema != "IFC2X3":
+            for definition in settings["product"].HasProperties or []:
+                if definition.Name == settings["name"]:
+                    return definition
 
-        return file.create_entity(
-            "IfcProfileProperties",
-            **{
-                "Name": settings["name"],
-                "ProfileDefinition": settings["product"],
-            }
-        )
+        kwargs = {}
+        kwargs["ProfileDefinition"] = settings["product"]
+        if file.schema != "IFC2X3":
+            kwargs["Name"] = settings["name"]
+
+        return file.create_entity("IfcProfileProperties", **kwargs)
diff --git a/src/ifcopenshell-python/ifcopenshell/api/resource/add_resource.py b/src/ifcopenshell-python/ifcopenshell/api/resource/add_resource.py
index 8131bed326..dd60840349 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/resource/add_resource.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/resource/add_resource.py
@@ -97,7 +97,7 @@ def add_resource(
             related_objects=[resource],
             relating_object=settings["parent_resource"],
         )
-    else:
+    elif file.schema != "IFC2X3":
         context = file.by_type("IfcContext")[0]
         ifcopenshell.api.run(
             "project.assign_declaration",
diff --git a/src/ifcopenshell-python/ifcopenshell/api/sequence/add_task.py b/src/ifcopenshell-python/ifcopenshell/api/sequence/add_task.py
index 6fd08d4b1d..152c74439b 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/sequence/add_task.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/sequence/add_task.py
@@ -175,6 +175,6 @@ def add_task(
             related_objects=[task],
             relating_object=settings["parent_task"],
         )
-        if settings["parent_task"].Identification:
+        if file.schema != "IFC2X3" and settings["parent_task"].Identification:
             task.Identification = settings["parent_task"].Identification + "." + str(len(rel.RelatedObjects))
     return task
diff --git a/src/ifcopenshell-python/ifcopenshell/api/sequence/add_work_schedule.py b/src/ifcopenshell-python/ifcopenshell/api/sequence/add_work_schedule.py
index 3fe8e1a003..a3bc13886c 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/sequence/add_work_schedule.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/sequence/add_work_schedule.py
@@ -90,11 +90,17 @@ def add_work_schedule(
         predefined_type=settings["predefined_type"],
         name=settings["name"],
     )
-    work_schedule.CreationDate = ifcopenshell.util.date.datetime2ifc(datetime.now(), "IfcDateTime")
+    if file.schema == "IFC2X3":
+        work_schedule.CreationDate = createIfcDateAndTime(file, datetime.now())
+    else:
+        work_schedule.CreationDate = ifcopenshell.util.date.datetime2ifc(datetime.now(), "IfcDateTime")
     user = ifcopenshell.api.owner.settings.get_user(file)
     if user:
         work_schedule.Creators = [user.ThePerson]
-    work_schedule.StartTime = ifcopenshell.util.date.datetime2ifc(settings["start_time"], "IfcDateTime")
+    if file.schema == "IFC2X3":
+        work_schedule.StartTime = createIfcDateAndTime(file, settings["start_time"])
+    else:
+        work_schedule.StartTime = ifcopenshell.util.date.datetime2ifc(settings["start_time"], "IfcDateTime")
     if settings["object_type"]:
         work_schedule.ObjectType = settings["object_type"]
     if settings["work_plan"]:
@@ -106,7 +112,7 @@ def add_work_schedule(
                 "relating_object": settings["work_plan"],
             }
         )
-    else:
+    elif file.schema != "IFC2X3":
         # TODO: this is an ambiguity by buildingSMART
         # See https://forums.buildingsmart.org/t/is-the-ifcworkschedule-project-declaration-mutually-exclusive-to-aggregation-within-a-relating-ifcworkplan/3510
         context = file.by_type("IfcContext")[0]
@@ -117,3 +123,12 @@ def add_work_schedule(
             relating_context=context,
         )
     return work_schedule
+
+
+def createIfcDateAndTime(file: ifcopenshell.file, dt: datetime):
+    ifc_dt = file.create_entity("IfcDateAndTime")
+    ifc_dt.DateComponent = file.create_entity(
+        "IfcCalendarDate", **ifcopenshell.util.date.datetime2ifc(dt, "IfcCalendarDate")
+    )
+    ifc_dt.TimeComponent = file.create_entity("IfcLocalTime", **ifcopenshell.util.date.datetime2ifc(dt, "IfcLocalTime"))
+    return ifc_dt
diff --git a/src/ifcopenshell-python/ifcopenshell/api/style/assign_material_style.py b/src/ifcopenshell-python/ifcopenshell/api/style/assign_material_style.py
index 45bbb3a059..b1ddd3e298 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/style/assign_material_style.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/style/assign_material_style.py
@@ -177,11 +177,31 @@ class Usecase:
             representations.append(self.create_styled_representation())
             definition_representation.Representations = representations
 
-    def has_proposed_style(self, styled_item):
-        return any(s == self.settings["style"] for s in styled_item.Styles)
+    def has_proposed_style(self, styled_item: ifcopenshell.entity_instance) -> bool:
+        style = self.settings["style"]
+        styles = styled_item.Styles
+        if style in styles:
+            return True
+        if self.file.schema != "IFC4X3":
+            # IfcPresentationStyleAssignment is removed in IFC4X3
+            for s in styles:
+                if s.is_a("IfcPresentationStyleAssignment"):
+                    if style in s.Styles:
+                        return True
+        return False
 
-    def has_same_style_type(self, styled_item):
-        return any(s.is_a() == self.settings["style"].is_a() for s in styled_item.Styles)
+    def has_same_style_type(self, styled_item: ifcopenshell.entity_instance) -> bool:
+        style = self.settings["style"]
+        style_class = style.is_a()
+        for s in styled_item.Styles:
+            s_class = s.is_a()
+            if s_class == style_class:
+                return True
+            elif s_class == "IfcPresentationStyleAssignment":
+                for ss in s.Styles:
+                    if ss.is_a() == style_class:
+                        return True
+        return False
 
     def create_new_definition_representation(self):
         representation = self.create_styled_representation()
@@ -214,6 +234,14 @@ class Usecase:
             return self.file.create_entity(
                 "IfcStyledItem", **{"Styles": [self.style], "Name": self.settings["style"].Name}
             )
-        reuse_item.Styles = (self.style,)
+
+        # IfcPresentationStyleAssignment we created end up not being used
+        # TODO: do not create IfcPresentationStyleAssignment in the first place
+        # as it might get removed
+        if reuse_item.is_a("IfcPresentationStyleAssignment") and self.style.is_a("IfcPresentationStyleAssignment"):
+            self.file.remove(self.style)
+            self.style = reuse_item
+
+        reuse_item.Styles = (self.settings["style"],)
         reuse_item.Name = self.settings["style"].Name
         return reuse_item
diff --git a/src/ifcopenshell-python/ifcopenshell/api/style/remove_surface_style.py b/src/ifcopenshell-python/ifcopenshell/api/style/remove_surface_style.py
index 4ec3b9a3f3..98674c5f84 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/style/remove_surface_style.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/style/remove_surface_style.py
@@ -45,22 +45,25 @@ def remove_surface_style(file: ifcopenshell.file, style: ifcopenshell.entity_ins
         # Remove the shading item
         ifcopenshell.api.run("style.remove_surface_style", model, style=shading)
     """
-    settings = {"style": style}
 
     to_delete = set()
-    if settings["style"].is_a("IfcSurfaceStyleWithTextures"):
-        for texture in settings["style"].Textures or []:
-            if texture.IsMappedBy:
-                for coordinate in texture.IsMappedBy:
-                    to_delete.add(coordinate)
-            else:
-                to_delete.add(texture)
+    if style.is_a("IfcSurfaceStyleWithTextures"):
+        textures = style.Textures
+        if file.schema == "IFC2X3":
+            to_delete.update(textures)
+        else:
+            for texture in textures:
+                if coords := texture.IsMappedBy:
+                    for coordinate in coords:
+                        to_delete.add(coordinate)
+                else:
+                    to_delete.add(texture)
 
-    for attribute in settings["style"]:
+    for attribute in style:
         if isinstance(attribute, ifcopenshell.entity_instance) and attribute.id():
             to_delete.add(attribute)
 
-    file.remove(settings["style"])
+    file.remove(style)
 
     for element in to_delete:
         ifcopenshell.util.element.remove_deep2(file, element)
diff --git a/src/ifcopenshell-python/ifcopenshell/api/style/unassign_material_style.py b/src/ifcopenshell-python/ifcopenshell/api/style/unassign_material_style.py
index 71189f8a88..17d0adfb3a 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/style/unassign_material_style.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/style/unassign_material_style.py
@@ -65,7 +65,14 @@ def unassign_material_style(
             for item in representation.Items:
                 if not item.is_a("IfcStyledItem"):
                     continue
-                styles = [s for s in item.Styles if s != settings["style"]]
+                styles = []
+                for s in item.Styles:
+                    if s == settings["style"]:
+                        continue
+                    if s.is_a("IfcPresentationStyleAssignment"):
+                        if s.Styles == (settings["style"],):
+                            continue
+                    styles.append(s)
                 if not styles:
                     file.remove(item)
                 elif len(styles) != len(item.Styles):
diff --git a/src/ifcopenshell-python/ifcopenshell/util/element.py b/src/ifcopenshell-python/ifcopenshell/util/element.py
index f57d1891bc..2430a2553a 100644
--- a/src/ifcopenshell-python/ifcopenshell/util/element.py
+++ b/src/ifcopenshell-python/ifcopenshell/util/element.py
@@ -158,6 +158,7 @@ def get_psets(
             if qtos_only and not definition.is_a("IfcElementQuantity"):
                 continue
             psets[definition.Name] = get_property_definition(definition, verbose=verbose)
+    # NOTE: doesn't account for IFC2X3 missing HasProperties
     elif element.is_a("IfcMaterialDefinition") or element.is_a("IfcProfileDef"):
         for definition in getattr(element, "HasProperties", None) or []:
             if qtos_only:
diff --git a/src/ifcopenshell-python/test/api/pset/test_add_pset.py b/src/ifcopenshell-python/test/api/pset/test_add_pset.py
index 9d18e16ee2..26c26f26af 100644
--- a/src/ifcopenshell-python/test/api/pset/test_add_pset.py
+++ b/src/ifcopenshell-python/test/api/pset/test_add_pset.py
@@ -38,13 +38,16 @@ class TestAddPset(test.bootstrap.IFC4):
         material = ifcopenshell.api.run("material.add_material", self.file)
         pset = ifcopenshell.api.run("pset.add_pset", self.file, product=material, name="Pset_MaterialCommon")
         assert pset.is_a("IfcMaterialProperties")
-        assert "Pset_MaterialCommon" in ifcopenshell.util.element.get_psets(material)
+        assert pset.Name == "Pset_MaterialCommon"
+        assert pset.Material == material
 
     def test_adding_a_pset_to_a_profile(self):
         profile = ifcopenshell.api.run("profile.add_parameterized_profile", self.file, ifc_class="IfcCircleProfileDef")
         pset = ifcopenshell.api.run("pset.add_pset", self.file, product=profile, name="Pset_ProfileMechanical")
         assert pset.is_a("IfcProfileProperties")
-        assert "Pset_ProfileMechanical" in ifcopenshell.util.element.get_psets(profile)
+        if self.file.schema != "IFC2X3":
+            assert pset.Name == "Pset_ProfileMechanical"
+        assert pset.ProfileDefinition == profile
 
     def test_adding_a_pset_to_a_context(self):
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcProject")
@@ -53,7 +56,7 @@ class TestAddPset(test.bootstrap.IFC4):
         assert "Custom_Pset" in ifcopenshell.util.element.get_psets(element)
 
 
-class TestAddPsetIFC2X3(test.bootstrap.IFC2X3):
+class TestAddPsetIFC2X3(test.bootstrap.IFC2X3, TestAddPset):
     def test_adding_a_pset_to_a_project(self):
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcProject")
         pset = ifcopenshell.api.run("pset.add_pset", self.file, product=element, name="Custom_Pset")
diff --git a/src/ifcopenshell-python/test/api/resource/test_calculate_resource_work.py b/src/ifcopenshell-python/test/api/resource/test_calculate_resource_work.py
index 83a9d9303d..e81e47f2fc 100644
--- a/src/ifcopenshell-python/test/api/resource/test_calculate_resource_work.py
+++ b/src/ifcopenshell-python/test/api/resource/test_calculate_resource_work.py
@@ -21,6 +21,8 @@ import ifcopenshell.api
 import ifcopenshell.util.constraint
 
 
+# NOTE: resource module features relies on entities introduced in IFC4
+# therefore no IFC2X3 tests
 class TestCalculateResourceWork(test.bootstrap.IFC4):
     def test_calculating_resource_work_based_on_a_daily_productivity_rate(self):
         ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcProject")
diff --git a/src/ifcopenshell-python/test/api/root/test_create_entity.py b/src/ifcopenshell-python/test/api/root/test_create_entity.py
index 49fc0891c2..9ec93d8933 100644
--- a/src/ifcopenshell-python/test/api/root/test_create_entity.py
+++ b/src/ifcopenshell-python/test/api/root/test_create_entity.py
@@ -23,22 +23,22 @@ import ifcopenshell.api
 class TestCreateEntity(test.bootstrap.IFC4):
     def test_creating_a_simple_entity_with_automatic_global_id(self):
         wall = ifcopenshell.api.run(
-            "root.create_entity", self.file, ifc_class="IfcWall", predefined_type="SOLIDWALL", name="Foo"
+            "root.create_entity", self.file, ifc_class="IfcRailing", predefined_type="HANDRAIL", name="Foo"
         )
-        assert wall.is_a() == "IfcWall"
+        assert wall.is_a() == "IfcRailing"
         assert len(wall.GlobalId) == 22
         assert wall.Name == "Foo"
-        assert wall.PredefinedType == "SOLIDWALL"
+        assert wall.PredefinedType == "HANDRAIL"
 
     def test_handling_predefined_types(self):
-        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall", name="Foo")
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcRailing", name="Foo")
         assert element.PredefinedType is None
         element = ifcopenshell.api.run(
-            "root.create_entity", self.file, ifc_class="IfcWall", predefined_type="SHEAR", name="Foo"
+            "root.create_entity", self.file, ifc_class="IfcRailing", predefined_type="HANDRAIL", name="Foo"
         )
-        assert element.PredefinedType == "SHEAR"
+        assert element.PredefinedType == "HANDRAIL"
         element = ifcopenshell.api.run(
-            "root.create_entity", self.file, ifc_class="IfcWall", predefined_type="Foobar", name="Foo"
+            "root.create_entity", self.file, ifc_class="IfcRailing", predefined_type="Foobar", name="Foo"
         )
         assert element.PredefinedType == "USERDEFINED"
         assert element.ObjectType == "Foobar"
@@ -47,11 +47,12 @@ class TestCreateEntity(test.bootstrap.IFC4):
         )
         assert element.PredefinedType == "USERDEFINED"
         assert element.ElementType == "Foobar"
-        element = ifcopenshell.api.run(
-            "root.create_entity", self.file, ifc_class="IfcTaskType", predefined_type="Foobar", name="Foo"
-        )
-        assert element.PredefinedType == "USERDEFINED"
-        assert element.ProcessType == "Foobar"
+        if self.file.schema != "IFC2X3":
+            element = ifcopenshell.api.run(
+                "root.create_entity", self.file, ifc_class="IfcTaskType", predefined_type="Foobar", name="Foo"
+            )
+            assert element.PredefinedType == "USERDEFINED"
+            assert element.ProcessType == "Foobar"
 
     def test_setting_default_values_for_validity(self):
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWallType", name="Foo")
@@ -66,9 +67,14 @@ class TestCreateEntity(test.bootstrap.IFC4):
         assert element.ConstructionType == "NOTDEFINED"
         assert element.ParameterTakesPrecedence == False
         assert element.Sizeable == False
-        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcDoorType", name="Foo")
-        assert element.OperationType == "NOTDEFINED"
-        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWindowType", name="Foo")
-        assert element.PartitioningType == "NOTDEFINED"
+        if self.file.schema != "IFC2X3":
+            element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcDoorType", name="Foo")
+            assert element.OperationType == "NOTDEFINED"
+            element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWindowType", name="Foo")
+            assert element.PartitioningType == "NOTDEFINED"
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcFurnitureType", name="Foo")
         assert element.AssemblyPlace == "NOTDEFINED"
+
+
+class TestCreateEntityIFC2X3(test.bootstrap.IFC2X3, TestCreateEntity):
+    pass
diff --git a/src/ifcopenshell-python/test/api/root/test_reassign_class.py b/src/ifcopenshell-python/test/api/root/test_reassign_class.py
index 17b3fd1801..80276686e9 100644
--- a/src/ifcopenshell-python/test/api/root/test_reassign_class.py
+++ b/src/ifcopenshell-python/test/api/root/test_reassign_class.py
@@ -18,14 +18,17 @@
 
 import test.bootstrap
 import ifcopenshell.api
+import ifcopenshell.util.element
 
 
 class TestReassignClass(test.bootstrap.IFC4):
     def test_reassigning_a_simple_class(self):
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        n_elements = len([e for e in self.file])
+        original_id = element.id()
         new = ifcopenshell.api.run("root.reassign_class", self.file, product=element, ifc_class="IfcSlab")
-        assert len([e for e in self.file]) == 1
-        assert new.id() == 1
+        assert len([e for e in self.file]) == n_elements
+        assert new.id() == original_id
         assert new.is_a("IfcSlab")
 
     def test_reassigning_a_predefined_type(self):
@@ -92,3 +95,7 @@ class TestReassignClass(test.bootstrap.IFC4):
         # original clases are gone
         assert len(self.file.by_type("IfcWall")) == 0
         assert len(self.file.by_type("IfcWallType")) == 0
+
+
+class TestReassignClassIFC2X3(test.bootstrap.IFC2X3, TestReassignClass):
+    pass
diff --git a/src/ifcopenshell-python/test/api/root/test_remove_product.py b/src/ifcopenshell-python/test/api/root/test_remove_product.py
index 418bdbc503..91a2cf6e31 100644
--- a/src/ifcopenshell-python/test/api/root/test_remove_product.py
+++ b/src/ifcopenshell-python/test/api/root/test_remove_product.py
@@ -395,7 +395,7 @@ class TestRemoveProduct(test.bootstrap.IFC4):
 
     def test_removing_all_space_boundaries_of_an_element(self):
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
-        boundary = self.file.createIfcRelSpaceBoundary2ndLevel(
+        boundary = self.file.createIfcRelSpaceBoundary(
             GlobalId=ifcopenshell.guid.new(), RelatedBuildingElement=element
         )
         ifcopenshell.api.run("root.remove_product", self.file, product=element)
@@ -417,8 +417,8 @@ class TestRemoveProduct(test.bootstrap.IFC4):
 
     def test_removing_flow_control_elements(self):
         flow_element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcFlowSegment")
-        flow_control = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcController")
-        flow_control1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcController")
+        flow_control = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcDistributionControlElement")
+        flow_control1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcDistributionControlElement")
 
         ifcopenshell.api.run(
             "system.assign_flow_control",
@@ -439,8 +439,8 @@ class TestRemoveProduct(test.bootstrap.IFC4):
 
     def test_removing_flow_element_with_flow_controls(self):
         flow_element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcFlowSegment")
-        flow_control = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcController")
-        flow_control1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcController")
+        flow_control = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcDistributionControlElement")
+        flow_control1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcDistributionControlElement")
 
         ifcopenshell.api.run(
             "system.assign_flow_control",
@@ -456,3 +456,7 @@ class TestRemoveProduct(test.bootstrap.IFC4):
         )
         ifcopenshell.api.run("root.remove_product", self.file, product=flow_element)
         assert not self.file.by_type("IfcRelFlowControlElements")
+
+
+class TestRemoveProductIFC2X3(test.bootstrap.IFC2X3, TestRemoveProduct):
+    pass
diff --git a/src/ifcopenshell-python/test/api/sequence/test_assign_product.py b/src/ifcopenshell-python/test/api/sequence/test_assign_product.py
index 698752ebc7..f0973e2fd0 100644
--- a/src/ifcopenshell-python/test/api/sequence/test_assign_product.py
+++ b/src/ifcopenshell-python/test/api/sequence/test_assign_product.py
@@ -36,3 +36,7 @@ class TestAssignProduct(test.bootstrap.IFC4):
         ifcopenshell.api.run("sequence.assign_product", self.file, relating_product=wall, related_object=task)
         ifcopenshell.api.run("sequence.assign_product", self.file, relating_product=wall, related_object=task)
         assert wall.ReferencedBy[0].RelatedObjects == (task,)
+
+
+class TestAssignProductIFC2X3(test.bootstrap.IFC2X3, TestAssignProduct):
+    pass
diff --git a/src/ifcopenshell-python/test/api/sequence/test_calculate_task_duration.py b/src/ifcopenshell-python/test/api/sequence/test_calculate_task_duration.py
index 587f7be225..06f0ed367b 100644
--- a/src/ifcopenshell-python/test/api/sequence/test_calculate_task_duration.py
+++ b/src/ifcopenshell-python/test/api/sequence/test_calculate_task_duration.py
@@ -20,6 +20,8 @@ import test.bootstrap
 import ifcopenshell.api
 
 
+# NOTE: sequence module features relies on entities introduced in IFC4
+# therefore no IFC2X3 tests
 class TestCalculateTaskDuration(test.bootstrap.IFC4):
     def test_calculating_the_duration_based_on_a_labour_resource_with_work_hours(self):
         ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcProject")
diff --git a/src/ifcopenshell-python/test/api/sequence/test_cascade_schedule.py b/src/ifcopenshell-python/test/api/sequence/test_cascade_schedule.py
index 9e5f8aa308..dd921ec2ae 100644
--- a/src/ifcopenshell-python/test/api/sequence/test_cascade_schedule.py
+++ b/src/ifcopenshell-python/test/api/sequence/test_cascade_schedule.py
@@ -22,6 +22,8 @@ import test.bootstrap
 import ifcopenshell.api
 
 
+# NOTE: sequence module features relies on entities introduced in IFC4
+# therefore no IFC2X3 tests
 class TestCascadeSchedule(test.bootstrap.IFC4):
     def test_doing_nothing_if_the_task_has_no_successors(self):
         task = ifcopenshell.api.run("sequence.add_task", self.file)
diff --git a/src/ifcopenshell-python/test/api/sequence/test_edit_task_time.py b/src/ifcopenshell-python/test/api/sequence/test_edit_task_time.py
index 3e59d526bb..efd41b0176 100644
--- a/src/ifcopenshell-python/test/api/sequence/test_edit_task_time.py
+++ b/src/ifcopenshell-python/test/api/sequence/test_edit_task_time.py
@@ -21,6 +21,9 @@ import test.bootstrap
 import ifcopenshell.api
 
 
+# NOTE: IfcTaskTime was introduced in IFC4
+
+
 class TestEditTaskTime(test.bootstrap.IFC4):
     def test_editing_all_attributes(self):
         task_time = ifcopenshell.api.run("sequence.add_task_time", self.file, task=self.file.createIfcTask())
diff --git a/src/ifcopenshell-python/test/api/sequence/test_edit_work_time.py b/src/ifcopenshell-python/test/api/sequence/test_edit_work_time.py
index d200116878..ce024a1bca 100644
--- a/src/ifcopenshell-python/test/api/sequence/test_edit_work_time.py
+++ b/src/ifcopenshell-python/test/api/sequence/test_edit_work_time.py
@@ -21,6 +21,7 @@ import test.bootstrap
 import ifcopenshell.api
 
 
+# NOTE: IfcWorkTime was introduced in IFC4
 class TestEditWorkTime(test.bootstrap.IFC4):
     def test_run(self):
         work_time = self.file.createIfcWorkTime()
diff --git a/src/ifcopenshell-python/test/api/sequence/test_recalculate_schedule.py b/src/ifcopenshell-python/test/api/sequence/test_recalculate_schedule.py
index 74ef955d66..b08c38273c 100644
--- a/src/ifcopenshell-python/test/api/sequence/test_recalculate_schedule.py
+++ b/src/ifcopenshell-python/test/api/sequence/test_recalculate_schedule.py
@@ -22,6 +22,8 @@ import test.bootstrap
 import ifcopenshell.api
 
 
+# NOTE: sequence module features relies on entities introduced in IFC4
+# therefore no IFC2X3 tests
 # A good way for checking these is to recreate them in ProjectLibre
 class TestRecalculateSchedule(test.bootstrap.IFC4):
     def test_doing_nothing_if_the_task_has_no_time(self):
diff --git a/src/ifcopenshell-python/test/api/sequence/test_unassign_product.py b/src/ifcopenshell-python/test/api/sequence/test_unassign_product.py
index a70e45d06f..4dba192ef3 100644
--- a/src/ifcopenshell-python/test/api/sequence/test_unassign_product.py
+++ b/src/ifcopenshell-python/test/api/sequence/test_unassign_product.py
@@ -27,3 +27,7 @@ class TestUnassignProduct(test.bootstrap.IFC4):
         ifcopenshell.api.run("sequence.assign_product", self.file, relating_product=wall, related_object=task)
         ifcopenshell.api.run("sequence.unassign_product", self.file, relating_product=wall, related_object=task)
         assert len(self.file.by_type("IfcRelAssignsToProduct")) == 0
+
+
+class TestUnassignProductIFC2X3(test.bootstrap.IFC2X3, TestUnassignProduct):
+    pass
diff --git a/src/ifcopenshell-python/test/api/spatial/test_assign_container.py b/src/ifcopenshell-python/test/api/spatial/test_assign_container.py
index 533db20267..e4ca971319 100644
--- a/src/ifcopenshell-python/test/api/spatial/test_assign_container.py
+++ b/src/ifcopenshell-python/test/api/spatial/test_assign_container.py
@@ -121,3 +121,7 @@ class TestAssignContainer(test.bootstrap.IFC4):
         ifcopenshell.api.run("aggregate.assign_object", self.file, products=[subelement], relating_object=aggregate)
         ifcopenshell.api.run("spatial.assign_container", self.file, products=[subelement], relating_structure=element)
         assert not ifcopenshell.util.element.get_aggregate(subelement)
+
+
+class TestAssignContainerIFC2X3(test.bootstrap.IFC2X3, TestAssignContainer):
+    pass
diff --git a/src/ifcopenshell-python/test/api/spatial/test_unassign_container.py b/src/ifcopenshell-python/test/api/spatial/test_unassign_container.py
index 033b5cd333..d7f172817c 100644
--- a/src/ifcopenshell-python/test/api/spatial/test_unassign_container.py
+++ b/src/ifcopenshell-python/test/api/spatial/test_unassign_container.py
@@ -57,3 +57,7 @@ class TestUnassignContainer(test.bootstrap.IFC4):
         ifcopenshell.api.run("spatial.assign_container", self.file, products=[subelement], relating_structure=element)
         ifcopenshell.api.run("spatial.unassign_container", self.file, products=[subelement])
         assert len(self.file.by_type("IfcRelContainedInSpatialStructure")) == 0
+
+
+class TestUnassignContainerIFC2X3(test.bootstrap.IFC2X3, TestUnassignContainer):
+    pass
diff --git a/src/ifcopenshell-python/test/api/structural/test_add_structural_analysis_model.py b/src/ifcopenshell-python/test/api/structural/test_add_structural_analysis_model.py
index 1849bf33e8..9fb407530d 100644
--- a/src/ifcopenshell-python/test/api/structural/test_add_structural_analysis_model.py
+++ b/src/ifcopenshell-python/test/api/structural/test_add_structural_analysis_model.py
@@ -28,3 +28,7 @@ class TestAddStructuralAnalysisModel(test.bootstrap.IFC4):
         models = self.file.by_type("IfcStructuralAnalysisModel")
         assert subject == models[0]
         assert subject.is_a("IfcStructuralAnalysisModel")
+
+
+class TestAddStructuralAnalysisModelIFC2X3(test.bootstrap.IFC2X3, TestAddStructuralAnalysisModel):
+    pass
diff --git a/src/ifcopenshell-python/test/api/structural/test_assign_structural_analysis_model.py b/src/ifcopenshell-python/test/api/structural/test_assign_structural_analysis_model.py
index b89b061b4c..7146a53f59 100644
--- a/src/ifcopenshell-python/test/api/structural/test_assign_structural_analysis_model.py
+++ b/src/ifcopenshell-python/test/api/structural/test_assign_structural_analysis_model.py
@@ -37,3 +37,7 @@ class TestAssignStructuralAnalysisModel(test.bootstrap.IFC4):
         assert rel.is_a("IfcRelAssignsToGroup")
         assert rel.RelatingGroup == subject
         assert product in rel.RelatedObjects
+
+
+class TestAssignStructuralAnalysisModelIFC2X3(test.bootstrap.IFC2X3, TestAssignStructuralAnalysisModel):
+    pass
diff --git a/src/ifcopenshell-python/test/api/structural/test_edit_structural_analysis_model.py b/src/ifcopenshell-python/test/api/structural/test_edit_structural_analysis_model.py
index 40f0fbfd4a..4527a0d3d8 100644
--- a/src/ifcopenshell-python/test/api/structural/test_edit_structural_analysis_model.py
+++ b/src/ifcopenshell-python/test/api/structural/test_edit_structural_analysis_model.py
@@ -34,3 +34,7 @@ class TestEditStructuralAnalysisModel(test.bootstrap.IFC4):
         models = self.file.by_type("IfcStructuralAnalysisModel")
         assert subject == models[0]
         assert subject.is_a("IfcStructuralAnalysisModel")
+
+
+class TestEditStructuralAnalysisModelIFC2X3(test.bootstrap.IFC2X3, TestEditStructuralAnalysisModel):
+    pass
diff --git a/src/ifcopenshell-python/test/api/structural/test_remove_structural_analysis_model.py b/src/ifcopenshell-python/test/api/structural/test_remove_structural_analysis_model.py
index 2fed85b618..a631d741aa 100644
--- a/src/ifcopenshell-python/test/api/structural/test_remove_structural_analysis_model.py
+++ b/src/ifcopenshell-python/test/api/structural/test_remove_structural_analysis_model.py
@@ -32,3 +32,7 @@ class TestRemoveStructuralAnalysisModel(test.bootstrap.IFC4):
         )
         models = self.file.by_type("IfcStructuralAnalysisModel")
         assert len(models) == 0
+
+
+class TestRemoveStructuralAnalysisModelIFC2X3(test.bootstrap.IFC2X3, TestRemoveStructuralAnalysisModel):
+    pass
diff --git a/src/ifcopenshell-python/test/api/structural/test_unassign_structural_analysis_model.py b/src/ifcopenshell-python/test/api/structural/test_unassign_structural_analysis_model.py
index 4168d2404b..b2269b8a3a 100644
--- a/src/ifcopenshell-python/test/api/structural/test_unassign_structural_analysis_model.py
+++ b/src/ifcopenshell-python/test/api/structural/test_unassign_structural_analysis_model.py
@@ -44,3 +44,7 @@ class TestUnassignStructuralAnalysisModel(test.bootstrap.IFC4):
         rels = self.file.by_type("IfcRelAssignsToGroup")
         assert len(models[0].IsGroupedBy) == 0
         assert len(rels) == 0
+
+
+class TestUnassignStructuralAnalysisModelIFC2X3(test.bootstrap.IFC2X3, TestUnassignStructuralAnalysisModel):
+    pass
diff --git a/src/ifcopenshell-python/test/api/style/test_add_surface_style.py b/src/ifcopenshell-python/test/api/style/test_add_surface_style.py
index b13fd8e7b7..80e297bed0 100644
--- a/src/ifcopenshell-python/test/api/style/test_add_surface_style.py
+++ b/src/ifcopenshell-python/test/api/style/test_add_surface_style.py
@@ -24,63 +24,77 @@ import ifcopenshell.api
 class TestAddSurfaceStyle(test.bootstrap.IFC4):
     def test_adding_a_surface_style(self):
         style = self.file.createIfcSurfaceStyle()
+        attrs = {"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}}
+        if self.file.schema != "IFC2X3":
+            attrs["Transparency"] = 0.5
         result = ifcopenshell.api.run(
             "style.add_surface_style",
             self.file,
             style=style,
             ifc_class="IfcSurfaceStyleShading",
-            attributes={"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}, "Transparency": 0.5},
+            attributes=attrs,
         )
         assert result.is_a("IfcSurfaceStyleShading")
         assert result.SurfaceColour.Red == 1
         assert result.SurfaceColour.Green == 1
         assert result.SurfaceColour.Blue == 1
-        assert result.Transparency == 0.5
+        if self.file.schema != "IFC2X3":
+            assert result.Transparency == 0.5
         assert style.Styles[0] == result
 
     def test_adding_a_rendering_style(self):
         style = self.file.createIfcSurfaceStyle()
+        attrs = {"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}}
+        if self.file.schema != "IFC2X3":
+            attrs["Transparency"] = 0.5
         result = ifcopenshell.api.run(
             "style.add_surface_style",
             self.file,
             style=style,
             ifc_class="IfcSurfaceStyleRendering",
-            attributes={"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}, "Transparency": 0.5},
+            attributes=attrs,
         )
         assert result.is_a("IfcSurfaceStyleRendering")
         assert result.SurfaceColour.Red == 1
         assert result.SurfaceColour.Green == 1
         assert result.SurfaceColour.Blue == 1
-        assert result.Transparency == 0.5
+        if self.file.schema != "IFC2X3":
+            assert result.Transparency == 0.5
         assert style.Styles[0] == result
 
     def test_not_adding_a_style_twice(self):
         style = self.file.createIfcSurfaceStyle()
+        attrs = {"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}}
+        if self.file.schema != "IFC2X3":
+            attrs["Transparency"] = 0.5
         ifcopenshell.api.run(
             "style.add_surface_style",
             self.file,
             style=style,
             ifc_class="IfcSurfaceStyleRendering",
-            attributes={"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}, "Transparency": 0.5},
+            attributes=attrs,
         )
         result = ifcopenshell.api.run(
             "style.add_surface_style",
             self.file,
             style=style,
             ifc_class="IfcSurfaceStyleRendering",
-            attributes={"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}, "Transparency": 0.5},
+            attributes=attrs,
         )
         assert style.Styles[0] == result
         assert len(style.Styles) == 1
 
     def test_adding_multiple_styles_of_different_types(self):
         style = self.file.createIfcSurfaceStyle()
+        attrs = {"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}}
+        if self.file.schema != "IFC2X3":
+            attrs["Transparency"] = 0.5
         result1 = ifcopenshell.api.run(
             "style.add_surface_style",
             self.file,
             style=style,
             ifc_class="IfcSurfaceStyleShading",
-            attributes={"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}, "Transparency": 0.5},
+            attributes=attrs,
         )
         result2 = ifcopenshell.api.run(
             "style.add_surface_style",
@@ -95,19 +109,26 @@ class TestAddSurfaceStyle(test.bootstrap.IFC4):
 
     def test_ensure_shading_and_rendering_are_mutually_exclusive_when_adding(self):
         style = self.file.createIfcSurfaceStyle()
+        attrs = {"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}}
+        if self.file.schema != "IFC2X3":
+            attrs["Transparency"] = 0.5
         ifcopenshell.api.run(
             "style.add_surface_style",
             self.file,
             style=style,
             ifc_class="IfcSurfaceStyleShading",
-            attributes={"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}, "Transparency": 0.5},
+            attributes=attrs,
         )
         result = ifcopenshell.api.run(
             "style.add_surface_style",
             self.file,
             style=style,
             ifc_class="IfcSurfaceStyleRendering",
-            attributes={"SurfaceColour": {"Name": "", "Red": 1, "Green": 1, "Blue": 1}, "Transparency": 0.5},
+            attributes=attrs,
         )
         assert style.Styles[0] == result
         assert len(style.Styles) == 1
+
+
+class TestAddSurfaceStyleIFC2X3(test.bootstrap.IFC2X3, TestAddSurfaceStyle):
+    pass
diff --git a/src/ifcopenshell-python/test/api/style/test_add_surface_textures.py b/src/ifcopenshell-python/test/api/style/test_add_surface_textures.py
index bdca230d99..590aa02399 100644
--- a/src/ifcopenshell-python/test/api/style/test_add_surface_textures.py
+++ b/src/ifcopenshell-python/test/api/style/test_add_surface_textures.py
@@ -21,6 +21,7 @@ import test.bootstrap
 import ifcopenshell.api
 
 
+# TODO: add ifc2x3 tests after add_surface_textures will support ifc2x3
 class TestAddSurfaceTexture(test.bootstrap.IFC4):
     def get_default_texture_data(self):
         return [
@@ -67,6 +68,7 @@ class TestAddSurfaceTexture(test.bootstrap.IFC4):
         for texture, data in zip(textures, texture_data):
             self.compare_texture_to_data(texture, data)
 
+    # NOTE: IfcTextureCoordinate doesn't have Maps in IFC2X3
     def test_add_surface_textures_from_data_with_uv_maps(self):
         texture_data = self.get_default_texture_data()
         texture_data[0]["uv_mode"] = "Generated"
diff --git a/src/ifcopenshell-python/test/api/style/test_assign_material_style.py b/src/ifcopenshell-python/test/api/style/test_assign_material_style.py
index 01325d8b99..14bdf5fda9 100644
--- a/src/ifcopenshell-python/test/api/style/test_assign_material_style.py
+++ b/src/ifcopenshell-python/test/api/style/test_assign_material_style.py
@@ -22,7 +22,7 @@ import ifcopenshell
 import ifcopenshell.api
 
 
-class TestAssignMaterialStyle(test.bootstrap.IFC4):
+class TestAssignMaterialStyleIFC2X3(test.bootstrap.IFC2X3):
     def test_run(self):
         material = ifcopenshell.api.run("material.add_material", self.file)
         context = self.file.createIfcGeometricRepresentationContext()
@@ -38,7 +38,12 @@ class TestAssignMaterialStyle(test.bootstrap.IFC4):
         assert len(representation.Items) == 1
         item = representation.Items[0]
         assert item.is_a("IfcStyledItem")
-        assert item.Styles == (style,)
+        if self.file.schema != "IFC2X3":
+            assert item.Styles == (style,)
+        else:
+            # IfcPresentationStyleAssignment
+            assert len(item.Styles[0]) == 1
+            assert item.Styles[0].Styles == (style,)
 
         style2 = self.file.createIfcSurfaceStyle()
         ifcopenshell.api.run("style.assign_material_style", self.file, material=material, style=style2, context=context)
@@ -48,8 +53,16 @@ class TestAssignMaterialStyle(test.bootstrap.IFC4):
         assert definition.Representations == (representation,)
         assert len(representation.Items) == 1
         assert representation.Items[0] == item
-        assert representation.Items[0].Styles == (style2,)
+        if self.file.schema != "IFC2X3":
+            assert representation.Items[0].Styles == (style2,)
+        else:
+            # IfcPresentationStyleAssignment
+            assert len(representation.Items[0].Styles) == 1
+            assert representation.Items[0].Styles == (style2,)
 
+
+class TestAssignMaterialStyleIFC4(test.bootstrap.IFC4, TestAssignMaterialStyleIFC2X3):
+    # IfcMaterialConstituentSet was added in IFC4
     def test_update_shape_aspect_representations_items_styles_if_material_is_part_of_matching_material_constituents(
         self,
     ):
diff --git a/src/ifcopenshell-python/test/api/style/test_edit_surface_style.py b/src/ifcopenshell-python/test/api/style/test_edit_surface_style.py
index 48282ece48..54665c70d3 100644
--- a/src/ifcopenshell-python/test/api/style/test_edit_surface_style.py
+++ b/src/ifcopenshell-python/test/api/style/test_edit_surface_style.py
@@ -25,15 +25,19 @@ class TestEditSurfaceStyle(test.bootstrap.IFC4):
     def test_editing_a_shading_style(self):
         colour = self.file.createIfcColourRgb(None, 0, 0, 0)
         style = self.file.createIfcSurfaceStyleShading(colour)
+        attrs = {"SurfaceColour": {"Red": 1, "Green": 1, "Blue": 1}}
+        if self.file.schema != "IFC2X3":
+            attrs["Transparency"] = 0.5
         ifcopenshell.api.run(
             "style.edit_surface_style",
             self.file,
             style=style,
-            attributes={"SurfaceColour": {"Red": 1, "Green": 1, "Blue": 1}, "Transparency": 0.5},
+            attributes=attrs,
         )
         assert style.SurfaceColour == colour
         assert list(colour) == [None, 1, 1, 1]
-        assert style.Transparency == 0.5
+        if self.file.schema != "IFC2X3":
+            assert style.Transparency == 0.5
 
     def test_editing_an_empty_colour_or_factor(self):
         for attribute in [
@@ -170,3 +174,7 @@ class TestEditSurfaceStyle(test.bootstrap.IFC4):
         )
         for attribute in attributes:
             assert tuple(getattr(style, attribute)) == (None, 1, 1, 1)
+
+
+class TestEditSurfaceStyleIFC2X3(test.bootstrap.IFC2X3, TestEditSurfaceStyle):
+    pass
diff --git a/src/ifcopenshell-python/test/api/style/test_remove_style.py b/src/ifcopenshell-python/test/api/style/test_remove_style.py
index 2b8620b442..857dec169f 100644
--- a/src/ifcopenshell-python/test/api/style/test_remove_style.py
+++ b/src/ifcopenshell-python/test/api/style/test_remove_style.py
@@ -34,3 +34,7 @@ class TestRemoveStyle(test.bootstrap.IFC4):
         styled_item = self.file.createIfcStyledItem(Styles=[style])
         ifcopenshell.api.run("style.remove_style", self.file, style=style)
         assert len(list(self.file)) == 0
+
+
+class TestRemoveStyleIFC2X3(test.bootstrap.IFC2X3, TestRemoveStyle):
+    pass
diff --git a/src/ifcopenshell-python/test/api/style/test_remove_surface_style.py b/src/ifcopenshell-python/test/api/style/test_remove_surface_style.py
index 2722a1de9a..01394cda6c 100644
--- a/src/ifcopenshell-python/test/api/style/test_remove_surface_style.py
+++ b/src/ifcopenshell-python/test/api/style/test_remove_surface_style.py
@@ -21,7 +21,7 @@ import test.bootstrap
 import ifcopenshell.api
 
 
-class TestRemoveSurfaceStyle(test.bootstrap.IFC4):
+class TestRemoveSurfaceStyleIFC2X3(test.bootstrap.IFC2X3):
     def test_removing_a_shading_style(self):
         style = self.file.createIfcSurfaceStyleShading(SurfaceColour=self.file.createIfcColourRgb(None, 1, 1, 1))
         ifcopenshell.api.run("style.remove_surface_style", self.file, style=style)
@@ -33,13 +33,6 @@ class TestRemoveSurfaceStyle(test.bootstrap.IFC4):
         ifcopenshell.api.run("style.remove_surface_style", self.file, style=style)
         assert len(list(self.file)) == 0
 
-    def test_removing_a_texture_style_with_all_of_its_coordinates(self):
-        texture = self.file.createIfcImageTexture()
-        coordinates = self.file.createIfcTextureCoordinateGenerator(Maps=[texture])
-        style = self.file.createIfcSurfaceStyleWithTextures(Textures=[texture])
-        ifcopenshell.api.run("style.remove_surface_style", self.file, style=style)
-        assert len(list(self.file)) == 0
-
     def test_removing_a_rendering_style(self):
         style = self.file.createIfcSurfaceStyleRendering(
             SurfaceColour=self.file.createIfcColourRgb(None, 1, 1, 1),
@@ -55,3 +48,13 @@ class TestRemoveSurfaceStyle(test.bootstrap.IFC4):
         g = ifcopenshell.file.from_string(self.file.wrapped_data.to_string())
         ifcopenshell.api.run("style.remove_surface_style", g, style=g.by_type("IfcSurfaceStyleRendering")[0])
         assert len(list(g)) == 0
+
+
+class TestRemoveSurfaceStyleIFC4(test.bootstrap.IFC4, TestRemoveSurfaceStyleIFC2X3):
+    # IfcTextureCoordinateGenerator doesn't have Maps in IFC2X3
+    def test_removing_a_texture_style_with_all_of_its_coordinates(self):
+        texture = self.file.createIfcImageTexture()
+        coordinates = self.file.createIfcTextureCoordinateGenerator(Maps=[texture])
+        style = self.file.createIfcSurfaceStyleWithTextures(Textures=[texture])
+        ifcopenshell.api.run("style.remove_surface_style", self.file, style=style)
+        assert len(list(self.file)) == 0
diff --git a/src/ifcopenshell-python/test/api/style/test_unassign_material_style.py b/src/ifcopenshell-python/test/api/style/test_unassign_material_style.py
index 47c6e6a928..f1e2b1c8a3 100644
--- a/src/ifcopenshell-python/test/api/style/test_unassign_material_style.py
+++ b/src/ifcopenshell-python/test/api/style/test_unassign_material_style.py
@@ -22,7 +22,7 @@ import ifcopenshell
 import ifcopenshell.api
 
 
-class TestAssignMaterialStyle(test.bootstrap.IFC4):
+class TestUnassignMaterialStyleIFC2X3(test.bootstrap.IFC2X3):
     def test_run(self):
         material = ifcopenshell.api.run("material.add_material", self.file)
         context = self.file.createIfcGeometricRepresentationContext()
@@ -36,7 +36,12 @@ class TestAssignMaterialStyle(test.bootstrap.IFC4):
         ifcopenshell.api.run(
             "style.unassign_material_style", self.file, material=material, style=style2, context=context
         )
-        assert item.Styles == (style,)
+        if self.file.schema != "IFC2X3":
+            assert item.Styles == (style,)
+        else:
+            # IfcPresentationStyleAssignment
+            assert len(item.Styles) == 1
+            assert item.Styles[0].Styles == (style,)
 
         # unassign last style
         ifcopenshell.api.run(
@@ -46,6 +51,9 @@ class TestAssignMaterialStyle(test.bootstrap.IFC4):
         assert len(self.file.by_type("IfcStyledRepresentation")) == 0
         assert len(self.file.by_type("IfcStyledItem")) == 0
 
+
+class TestUnassignMaterialStyleIFC4(test.bootstrap.IFC4, TestUnassignMaterialStyleIFC2X3):
+    # IfcMaterialConstituentSet was added in IFC4
     def test_update_shape_aspect_representaitons_items_styles_if_material_is_part_of_matching_material_constituents(
         self,
     ):
diff --git a/src/ifcopenshell-python/test/api/system/test_add_port.py b/src/ifcopenshell-python/test/api/system/test_add_port.py
index e1d74be2e9..5a1a06f59f 100644
--- a/src/ifcopenshell-python/test/api/system/test_add_port.py
+++ b/src/ifcopenshell-python/test/api/system/test_add_port.py
@@ -26,6 +26,10 @@ class TestAddPort(test.bootstrap.IFC4):
         assert ifcopenshell.api.run("system.add_port", self.file).is_a("IfcDistributionPort")
 
     def test_assigning_a_port_as_well_if_an_element_is_specified(self):
-        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcChiller")
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcFlowTerminal")
         port = ifcopenshell.api.run("system.add_port", self.file, element=element)
         assert ifcopenshell.util.system.get_ports(element) == [port]
+
+
+class TestAddPortIFC2X3(test.bootstrap.IFC2X3, TestAddPort):
+    pass
diff --git a/src/ifcopenshell-python/test/api/system/test_add_system.py b/src/ifcopenshell-python/test/api/system/test_add_system.py
index 07c304cbba..2c0ed31b8a 100644
--- a/src/ifcopenshell-python/test/api/system/test_add_system.py
+++ b/src/ifcopenshell-python/test/api/system/test_add_system.py
@@ -25,4 +25,11 @@ class TestAddSystem(test.bootstrap.IFC4):
         system = ifcopenshell.api.run("system.add_system", self.file, ifc_class="IfcSystem")
         system2 = ifcopenshell.api.run("system.add_system", self.file, ifc_class="IfcDistributionSystem")
         assert system.is_a("IfcSystem")
-        assert system2.is_a("IfcDistributionSystem")
+        if self.file.schema == "IFC2X3":
+            assert system2.is_a("IfcSystem")
+        else:
+            assert system2.is_a("IfcDistributionSystem")
+
+
+class TestAddSystemIFC2X3(test.bootstrap.IFC2X3, TestAddSystem):
+    pass
diff --git a/src/ifcopenshell-python/test/api/system/test_assign_flow_control.py b/src/ifcopenshell-python/test/api/system/test_assign_flow_control.py
index ac78e66633..038b22b83a 100644
--- a/src/ifcopenshell-python/test/api/system/test_assign_flow_control.py
+++ b/src/ifcopenshell-python/test/api/system/test_assign_flow_control.py
@@ -23,7 +23,7 @@ import ifcopenshell.api
 class TestAssignFlowControl(test.bootstrap.IFC4):
     def test_run(self):
         flow_element = self.file.createIfcFlowSegment()
-        flow_control = self.file.createIfcController()
+        flow_control = self.file.create_entity("IfcDistributionControlElement")
 
         # simple assignment
         relation = ifcopenshell.api.run(
@@ -56,7 +56,7 @@ class TestAssignFlowControl(test.bootstrap.IFC4):
         assert relation is None
 
         # assigning another control to the same object
-        flow_control1 = self.file.createIfcController()
+        flow_control1 = self.file.create_entity("IfcDistributionControlElement")
         relation = ifcopenshell.api.run(
             "system.assign_flow_control",
             self.file,
@@ -66,3 +66,7 @@ class TestAssignFlowControl(test.bootstrap.IFC4):
         assert len(self.file.by_type("IfcRelFlowControlElements")) == 1
         assert relation.RelatingFlowElement == flow_element
         assert set(relation.RelatedControlElements) == set((flow_control, flow_control1))
+
+
+class TestAssignFlowControlIFC2X3(test.bootstrap.IFC2X3, TestAssignFlowControl):
+    pass
diff --git a/src/ifcopenshell-python/test/api/system/test_connect_port.py b/src/ifcopenshell-python/test/api/system/test_connect_port.py
index ab1325389a..8904ae05b6 100644
--- a/src/ifcopenshell-python/test/api/system/test_connect_port.py
+++ b/src/ifcopenshell-python/test/api/system/test_connect_port.py
@@ -108,8 +108,12 @@ class TestConnectPort(test.bootstrap.IFC4):
     def test_connecting_ports_with_a_realising_element(self):
         port = ifcopenshell.api.run("system.add_port", self.file)
         port2 = ifcopenshell.api.run("system.add_port", self.file)
-        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcDuctFitting")
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcFlowFitting")
         ifcopenshell.api.run("system.connect_port", self.file, port1=port, port2=port2, element=element)
         assert self.file.by_type("IfcRelConnectsPorts")[0].RealizingElement == element
         ifcopenshell.api.run("system.connect_port", self.file, port1=port, port2=port2)
         assert self.file.by_type("IfcRelConnectsPorts")[0].RealizingElement is None
+
+
+class TestConnectPortIFC2X3(test.bootstrap.IFC2X3, TestConnectPort):
+    pass
diff --git a/src/ifcopenshell-python/test/api/system/test_disconnect_port.py b/src/ifcopenshell-python/test/api/system/test_disconnect_port.py
index 8b2ade0310..a19b665700 100644
--- a/src/ifcopenshell-python/test/api/system/test_disconnect_port.py
+++ b/src/ifcopenshell-python/test/api/system/test_disconnect_port.py
@@ -21,7 +21,7 @@ import ifcopenshell.api
 import ifcopenshell.util.system
 
 
-class TestConnectPort(test.bootstrap.IFC4):
+class TestDisconnectPort(test.bootstrap.IFC4):
     def test_disconnecting_a_port(self):
         port = ifcopenshell.api.run("system.add_port", self.file)
         port2 = ifcopenshell.api.run("system.add_port", self.file)
@@ -30,3 +30,7 @@ class TestConnectPort(test.bootstrap.IFC4):
         assert port.FlowDirection == None
         assert port2.FlowDirection == None
         assert len(self.file.by_type("IfcRelConnectsPorts")) == 0
+
+
+class TestDisconnectPortIFC2X3(test.bootstrap.IFC2X3, TestDisconnectPort):
+    pass
diff --git a/src/ifcopenshell-python/test/api/system/test_remove_system.py b/src/ifcopenshell-python/test/api/system/test_remove_system.py
index 86118cf943..0e1797eae1 100644
--- a/src/ifcopenshell-python/test/api/system/test_remove_system.py
+++ b/src/ifcopenshell-python/test/api/system/test_remove_system.py
@@ -27,7 +27,7 @@ class TestRemoveSystem(test.bootstrap.IFC4):
         assert len(self.file.by_type("IfcSystem")) == 0
 
     def test_removing_orphaned_group_relationships(self):
-        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcPump")
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcFlowTerminal")
         system = ifcopenshell.api.run("system.add_system", self.file, ifc_class="IfcSystem")
         ifcopenshell.api.run("system.assign_system", self.file, product=element, system=system)
         ifcopenshell.api.run("system.remove_system", self.file, system=system)
@@ -41,3 +41,7 @@ class TestRemoveSystem(test.bootstrap.IFC4):
         assert not self.file.by_type("IfcRelDefinesByProperties")
         assert not self.file.by_type("IfcPropertySet")
         assert not self.file.by_type("IfcPropertySingleValue")
+
+
+class TestRemoveSystemIFC2X3(test.bootstrap.IFC2X3, TestRemoveSystem):
+    pass
diff --git a/src/ifcopenshell-python/test/api/system/test_unassign_flow_control.py b/src/ifcopenshell-python/test/api/system/test_unassign_flow_control.py
index bb881367e6..873c497505 100644
--- a/src/ifcopenshell-python/test/api/system/test_unassign_flow_control.py
+++ b/src/ifcopenshell-python/test/api/system/test_unassign_flow_control.py
@@ -23,7 +23,7 @@ import ifcopenshell.api
 class TestUnassignFlowControl(test.bootstrap.IFC4):
     def test_run(self):
         flow_element = self.file.createIfcFlowSegment()
-        flow_control = self.file.createIfcController()
+        flow_control = self.file.create_entity("IfcDistributionControlElement")
 
         # assign and unassign
         relation = ifcopenshell.api.run(
@@ -41,7 +41,7 @@ class TestUnassignFlowControl(test.bootstrap.IFC4):
         assert len(self.file.by_type("IfcRelFlowControlElements")) == 0
 
         # 1 element 2 controls
-        flow_control1 = self.file.createIfcController()
+        flow_control1 = self.file.create_entity("IfcDistributionControlElement")
         relation = ifcopenshell.api.run(
             "system.assign_flow_control",
             self.file,
@@ -62,3 +62,7 @@ class TestUnassignFlowControl(test.bootstrap.IFC4):
         )
         assert len(self.file.by_type("IfcRelFlowControlElements")) == 1
         assert relation.RelatedControlElements == (flow_control,)
+
+
+class TestUnassignFlowControlIFC2X3(test.bootstrap.IFC2X3, TestUnassignFlowControl):
+    pass