diff --git a/changelog.d/uk-gate-team-signing-key.added.md b/changelog.d/uk-gate-team-signing-key.added.md
new file mode 100644
index 0000000000..af1ca3f668
--- /dev/null
+++ b/changelog.d/uk-gate-team-signing-key.added.md
@@ -0,0 +1 @@
+Register a second UK gate signing key, held in the team's shared agent store, so cuts can be built and signed without the first builder's key. The key that signed every earlier cut stays active.
diff --git a/packages/microcosm-data/src/microcosm/data/gate_signing_keys.py b/packages/microcosm-data/src/microcosm/data/gate_signing_keys.py
index a875c08334..9aa12864b0 100644
--- a/packages/microcosm-data/src/microcosm/data/gate_signing_keys.py
+++ b/packages/microcosm-data/src/microcosm/data/gate_signing_keys.py
@@ -113,6 +113,25 @@ class GateSigningKey:
                 ),
             )
         ),
+        "dd31e32563854596d983a71a6519c6b7860a7c1f63ffb80dbe679d5d34c4de8c": (
+            GateSigningKey(
+                key_sha256=(
+                    "dd31e32563854596d983a71a6519c6b7860a7c1f63ffb80dbe679d5d34c4de8c"
+                ),
+                label="uk-gate-team-2026",
+                status="active",
+                custodian="the PolicyEngine team (Max Ghenis's shared agent store)",
+                held_in=(
+                    "agent-secret service microcosm/uk-gate-signing-key-team, "
+                    "account maxghenis, on Max's build Mac"
+                ),
+                registered="2026-10-22",
+                evidence=(
+                    "Generated 2026-10-22 for team-built cuts (microcosm#1348); "
+                    "never printed or committed."
+                ),
+            )
+        ),
     }
 )