diff --git a/CHANGELOG.md b/CHANGELOG.md
index 58d50eea..fea83611 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -47,6 +47,15 @@ PyPI version — not the changelog header.
   relays. Stall logic extracted into a `StallTracker` for clarity; +9 tests
   (142 green), devpulse audit 100%. (devpulse)
 
+- **`is_owner()` now case-folds — `is_owner('DEVPULSE')` matches `is_owner('devpulse')`
+  (issue #679).** The spawn-registry resolver (`registry.py:382`) `@`-normalized the
+  email but never lowercased, so a mixed-case branch name (registry names are
+  mixed-case: `DEVPULSE` vs `devpulse`) returned `False` against the seated owner.
+  Harmless today (the only caller lowercases first) but the frozen TDPLAN-0012
+  contract promises normalization, and PART-4 owner-gating may pass a raw name.
+  Now lowercases both sides; verified live (every case variant of the owner → True,
+  non-owners → False) + a case-insensitivity test (316 green). (@spawn, verified devpulse)
+
 - **`aipass install` no longer hard-fails (exit 2, silently) when it can't create
   global symlinks (issue #660 follow-up).** `setup.sh` runs under
   `set -euo pipefail`; the #660 `safe_symlink` refactor returns `2` on `ln`
diff --git a/src/aipass/spawn/apps/handlers/registry.py b/src/aipass/spawn/apps/handlers/registry.py
index 43409ae4..78c03fb2 100644
--- a/src/aipass/spawn/apps/handlers/registry.py
+++ b/src/aipass/spawn/apps/handlers/registry.py
@@ -379,10 +379,10 @@ def is_owner(email, start_path=None):
     """
     if not email:
         return False
-    normalized = email if email.startswith("@") else f"@{email}"
+    normalized = (email if email.startswith("@") else f"@{email}").lower()
     owner = get_owner(start_path=start_path)
     if owner is None:
         return False
     owner_email = owner.get("email", "")
-    owner_normalized = owner_email if owner_email.startswith("@") else f"@{owner_email}"
+    owner_normalized = (owner_email if owner_email.startswith("@") else f"@{owner_email}").lower()
     return normalized == owner_normalized
diff --git a/src/aipass/spawn/tests/test_owner_resolver.py b/src/aipass/spawn/tests/test_owner_resolver.py
index 7fdc219a..75e3507b 100644
--- a/src/aipass/spawn/tests/test_owner_resolver.py
+++ b/src/aipass/spawn/tests/test_owner_resolver.py
@@ -154,6 +154,15 @@ class TestIsOwner:
         with patch("aipass.spawn.apps.handlers.registry.find_registry", return_value=registry_with_owner):
             assert is_owner("devpulse", start_path=tmp_path) is True
 
+    def test_case_insensitive(self, registry_with_owner, tmp_path):
+        from aipass.spawn.apps.handlers.registry import is_owner
+
+        with patch("aipass.spawn.apps.handlers.registry.find_registry", return_value=registry_with_owner):
+            assert is_owner("DEVPULSE", start_path=tmp_path) is True
+            assert is_owner("@DEVPULSE", start_path=tmp_path) is True
+            assert is_owner("DevPulse", start_path=tmp_path) is True
+            assert is_owner("ALPHA", start_path=tmp_path) is False
+
     def test_false_for_non_owner(self, registry_with_owner, tmp_path):
         from aipass.spawn.apps.handlers.registry import is_owner