diff --git a/sdk/basyx/aas/adapter/aasx.py b/sdk/basyx/aas/adapter/aasx.py
index 8bb5958f6..7ddf91316 100644
--- a/sdk/basyx/aas/adapter/aasx.py
+++ b/sdk/basyx/aas/adapter/aasx.py
@@ -824,15 +824,25 @@ def add_file(self, name: str, file: IO[bytes], content_type: str) -> str:
         if hash not in self._store:
             self._store[hash] = data
             self._store_refcount[hash] = 0
-        name_map_data = (hash, content_type)
+        return self._assign_unique_name(name, hash, content_type)
+
+    def rename_file(self, old_name: str, new_name: str) -> str:
+        if old_name not in self._name_map:
+            raise KeyError(f"File with name {old_name} not found in SupplementaryFileContainer.")
+        if new_name == old_name:
+            return new_name
+        file_hash, file_content_type = self._name_map[old_name]
+        del self._name_map[old_name]
+        return self._assign_unique_name(new_name, file_hash, file_content_type)
+
+    def _assign_unique_name(self, name: str, sha: bytes, content_type: str) -> str:
         new_name = name
         i = 1
         while True:
             if new_name not in self._name_map:
-                self._name_map[new_name] = name_map_data
-                self._store_refcount[hash] += 1
+                self._name_map[new_name] = (sha, content_type)
                 return new_name
-            elif self._name_map[new_name] == name_map_data:
+            elif self._name_map[new_name] == (sha, content_type):
                 return new_name
             new_name = self._append_counter(name, i)
             i += 1
diff --git a/sdk/test/adapter/aasx/test_aasx.py b/sdk/test/adapter/aasx/test_aasx.py
index a83c60186..caf4e24c9 100644
--- a/sdk/test/adapter/aasx/test_aasx.py
+++ b/sdk/test/adapter/aasx/test_aasx.py
@@ -22,19 +22,43 @@ class TestAASXUtils(unittest.TestCase):
     def test_supplementary_file_container(self) -> None:
         container = aasx.DictSupplementaryFileContainer()
         with open(os.path.join(os.path.dirname(__file__), 'TestFile.pdf'), 'rb') as f:
-            new_name = container.add_file("/TestFile.pdf", f, "application/pdf")
+            saved_file_name = container.add_file("/TestFile.pdf", f, "application/pdf")
             # Name should not be modified, since there is no conflict
-            self.assertEqual("/TestFile.pdf", new_name)
+            self.assertEqual("/TestFile.pdf", saved_file_name)
             f.seek(0)
-            container.add_file("/TestFile.pdf", f, "application/pdf")
+            # Add the same file again with the same name
+            same_file_with_same_name = container.add_file("/TestFile.pdf", f, "application/pdf")
         # Name should not be modified, since there is still no conflict
-        self.assertEqual("/TestFile.pdf", new_name)
+        self.assertEqual("/TestFile.pdf", same_file_with_same_name)
 
+        # Add other file with the same name to create a conflict
         with open(__file__, 'rb') as f:
-            new_name = container.add_file("/TestFile.pdf", f, "application/pdf")
+            saved_file_name_2 = container.add_file("/TestFile.pdf", f, "application/pdf")
         # Now, we have a conflict
-        self.assertNotEqual("/TestFile.pdf", new_name)
-        self.assertIn(new_name, container)
+        self.assertNotEqual(saved_file_name, saved_file_name_2)
+        self.assertIn(saved_file_name_2, container)
+
+        # Rename file to a new unique name
+        renamed = container.rename_file(saved_file_name_2, "/RenamedTestFile.pdf")
+        self.assertIn(renamed, container)
+        # Old name should no longer exist
+        self.assertNotIn(saved_file_name_2, container)
+        self.assertEqual(renamed, "/RenamedTestFile.pdf")
+
+        # Renaming to the same name should be no-op
+        renamed_same = container.rename_file(renamed, renamed)
+        self.assertEqual(renamed, renamed_same)
+
+        # Renaming to an existing name should create a conflict
+        renamed_conflict = container.rename_file(renamed, "/TestFile.pdf")
+        self.assertNotEqual(renamed_conflict, "/TestFile.pdf")
+        self.assertIn(renamed_conflict, container)
+
+        # Renaming a non-existing file should raise KeyError
+        with self.assertRaises(KeyError):
+            container.rename_file("/NonExistingFile.pdf", "/AnotherName.pdf")
+
+        new_name = renamed_conflict
 
         # Check metadata
         self.assertEqual("application/pdf", container.get_content_type("/TestFile.pdf"))