diff --git a/openstackclient/network/v2/_tag.py b/openstackclient/network/v2/_tag.py
index d1e59937fa..ce39f35ec0 100644
--- a/openstackclient/network/v2/_tag.py
+++ b/openstackclient/network/v2/_tag.py
@@ -102,10 +102,10 @@ def update_tags_for_set(client, obj, parsed_args):
     if parsed_args.no_tag:
         tags = set()
     else:
-        tags = set(obj.tags)
+        tags = set(obj.tags or [])
     if parsed_args.tags:
         tags |= set(parsed_args.tags)
-    if set(obj.tags) != tags:
+    if set(obj.tags or []) != tags:
         client.set_tags(obj, list(tags))
 
 
diff --git a/releasenotes/notes/bug-1735836-9be6d777a6e6410b.yaml b/releasenotes/notes/bug-1735836-9be6d777a6e6410b.yaml
new file mode 100644
index 0000000000..346048532d
--- /dev/null
+++ b/releasenotes/notes/bug-1735836-9be6d777a6e6410b.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    ``openstack subnet create`` failed with a NoneType exception when
+    there were no tags.
+    [Bug `1735836 <https://bugs.launchpad.net/python-openstackclient/+bug/1735836>`_]