diff --git a/homeassistant/components/knx/diagnostics.py b/homeassistant/components/knx/diagnostics.py
index 6d523dda0f5..8f98089a567 100644
--- a/homeassistant/components/knx/diagnostics.py
+++ b/homeassistant/components/knx/diagnostics.py
@@ -52,8 +52,10 @@ async def async_get_config_entry_diagnostics(
     try:
         CONFIG_SCHEMA(raw_config)
     except vol.Invalid as ex:
-        diag["configuration_error"] = str(ex)
+        diag["yaml_configuration_error"] = str(ex)
     else:
-        diag["configuration_error"] = None
+        diag["yaml_configuration_error"] = None
+
+    diag["config_store"] = knx_module.config_store.data
 
     return diag
diff --git a/tests/components/knx/snapshots/test_diagnostic.ambr b/tests/components/knx/snapshots/test_diagnostic.ambr
index 4323dd113cd..674baa20e1e 100644
--- a/tests/components/knx/snapshots/test_diagnostic.ambr
+++ b/tests/components/knx/snapshots/test_diagnostic.ambr
@@ -9,7 +9,10 @@
       'rate_limit': 0,
       'state_updater': True,
     }),
-    'configuration_error': "extra keys not allowed @ data['knx']['wrong_key']",
+    'config_store': dict({
+      'entities': dict({
+      }),
+    }),
     'configuration_yaml': dict({
       'wrong_key': dict({
       }),
@@ -19,6 +22,7 @@
       'current_address': '0.0.0',
       'version': '0.0.0',
     }),
+    'yaml_configuration_error': "extra keys not allowed @ data['knx']['wrong_key']",
   })
 # ---
 # name: test_diagnostic_redact[hass_config0]
@@ -35,13 +39,17 @@
       'state_updater': True,
       'user_password': '**REDACTED**',
     }),
-    'configuration_error': None,
+    'config_store': dict({
+      'entities': dict({
+      }),
+    }),
     'configuration_yaml': None,
     'project_info': None,
     'xknx': dict({
       'current_address': '0.0.0',
       'version': '0.0.0',
     }),
+    'yaml_configuration_error': None,
   })
 # ---
 # name: test_diagnostics[hass_config0]
@@ -54,13 +62,17 @@
       'rate_limit': 0,
       'state_updater': True,
     }),
-    'configuration_error': None,
+    'config_store': dict({
+      'entities': dict({
+      }),
+    }),
     'configuration_yaml': None,
     'project_info': None,
     'xknx': dict({
       'current_address': '0.0.0',
       'version': '0.0.0',
     }),
+    'yaml_configuration_error': None,
   })
 # ---
 # name: test_diagnostics_project[hass_config0]
@@ -73,7 +85,50 @@
       'rate_limit': 0,
       'state_updater': True,
     }),
-    'configuration_error': None,
+    'config_store': dict({
+      'entities': dict({
+        'light': dict({
+          'knx_es_01J85ZKTFHSZNG4X9DYBE592TF': dict({
+            'entity': dict({
+              'device_info': None,
+              'entity_category': 'config',
+              'name': 'test',
+            }),
+            'knx': dict({
+              'color_temp_max': 6000,
+              'color_temp_min': 2700,
+              'ga_switch': dict({
+                'passive': list([
+                ]),
+                'state': '1/0/21',
+                'write': '1/1/21',
+              }),
+              'sync_state': True,
+            }),
+          }),
+        }),
+        'switch': dict({
+          'knx_es_9d97829f47f1a2a3176a7c5b4216070c': dict({
+            'entity': dict({
+              'device_info': 'knx_vdev_4c80a564f5fe5da701ed293966d6384d',
+              'entity_category': None,
+              'name': 'test',
+            }),
+            'knx': dict({
+              'ga_switch': dict({
+                'passive': list([
+                ]),
+                'state': '1/0/45',
+                'write': '1/1/45',
+              }),
+              'invert': False,
+              'respond_to_read': False,
+              'sync_state': True,
+            }),
+          }),
+        }),
+      }),
+    }),
     'configuration_yaml': None,
     'project_info': dict({
       'created_by': 'ETS5',
@@ -91,5 +146,6 @@
       'current_address': '0.0.0',
       'version': '0.0.0',
     }),
+    'yaml_configuration_error': None,
   })
 # ---
diff --git a/tests/components/knx/test_diagnostic.py b/tests/components/knx/test_diagnostic.py
index 1b63e4a3f9a..f3410644540 100644
--- a/tests/components/knx/test_diagnostic.py
+++ b/tests/components/knx/test_diagnostic.py
@@ -120,9 +120,13 @@ async def test_diagnostics_project(
     snapshot: SnapshotAssertion,
 ) -> None:
     """Test diagnostics."""
-    await knx.setup_integration()
+    await knx.setup_integration(
+        config_store_fixture="config_store_light_switch.json",
+        state_updater=False,
+    )
     knx.xknx.version = "0.0.0"
     # snapshot will contain project specific fields in `project_info`
+    # and UI configuration in `config_store`
     assert (
         await get_diagnostics_for_config_entry(hass, hass_client, mock_config_entry)
         == snapshot