diff --git a/CHANGELOG.md b/CHANGELOG.md
index 06dc05c38..f61a432ec 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ FEATURES:
 ENHANCEMENTS:
 
 BUG FIXES:
+* Cusotm actions fail on resources with a pipline ([#3646](https://github.com/microsoft/AzureTRE/issues/3646))
 
 ## 0.12.0 (July 27, 2023)
 
diff --git a/api_app/service_bus/helpers.py b/api_app/service_bus/helpers.py
index 050e48b83..5c791b6f7 100644
--- a/api_app/service_bus/helpers.py
+++ b/api_app/service_bus/helpers.py
@@ -63,8 +63,8 @@ async def update_resource_for_step(operation_step: OperationStep, resource_repo:
 
     parent_template = await resource_template_repo.get_template_by_name_and_version(step_resource.templateName, step_resource.templateVersion, step_resource.resourceType, step_resource_parent_service_name)
 
-    # if there are no pipelines, no need to continue with substitutions.
-    if not parent_template.pipeline:
+    # if there are no pipelines, or custom action, no need to continue with substitutions.
+    if not parent_template.pipeline or primary_action not in parent_template.pipeline.dict():
         return step_resource
 
     pipeline_primary_action = parent_template.pipeline.dict()[primary_action]