diff --git a/.changeset/904-init-execute-phase-normalize-branch.md b/.changeset/904-init-execute-phase-normalize-branch.md
new file mode 100644
index 000000000..3e1a3dd6c
--- /dev/null
+++ b/.changeset/904-init-execute-phase-normalize-branch.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 904
+---
+**`init execute-phase` and `cmdCommit` now produce correct `branch_name` when `project_code` is set** — the `{phase}` substitution in `phase_branch_template` now calls `normalizePhaseName()`, stripping the project-code prefix and zero-padding the number, so the generated branch is e.g. `gsd/phase-01-foundation` instead of `gsd/phase-CK-01-foundation`. Both the execute-phase output path (`src/init.cts`) and the pre-execution commit path (`src/commands.cts`) are fixed. (#904)
diff --git a/src/commands.cts b/src/commands.cts
index 0d72e81bc..78e37f5f4 100644
--- a/src/commands.cts
+++ b/src/commands.cts
@@ -547,7 +547,7 @@ function cmdCommit(cwd: string, message: string | undefined, files: string[] | u
         const phaseInfo = findPhaseInternal(cwd, phaseNum) as Record<string, unknown> | null;
         if (phaseInfo) {
           branchName = (config['phase_branch_template'] as string)
-            .replace('{phase}', phaseInfo['phase_number'] as string)
+            .replace('{phase}', normalizePhaseName(phaseInfo['phase_number']))
             .replace('{slug}', (phaseInfo['phase_slug'] as string) || 'phase');
         }
       }
diff --git a/src/init.cts b/src/init.cts
index 444ae31d3..a6379a169 100644
--- a/src/init.cts
+++ b/src/init.cts
@@ -260,7 +260,7 @@ function cmdInitExecutePhase(
       config.branching_strategy === 'phase' && phaseInfo
         ? (config.phase_branch_template as string)
             .replace('{project}', (config.project_code as string) || '')
-            .replace('{phase}', phaseInfo['phase_number'] as string)
+            .replace('{phase}', normalizePhaseName(phaseInfo['phase_number']))
             .replace('{slug}', (phaseInfo['phase_slug'] as string) || 'phase')
         : config.branching_strategy === 'milestone'
           ? (config.milestone_branch_template as string)
diff --git a/tests/init.test.cjs b/tests/init.test.cjs
index ec5957998..14bbe38ec 100644
--- a/tests/init.test.cjs
+++ b/tests/init.test.cjs
@@ -538,6 +538,35 @@ describe('init plan-phase zero-padded phase number (bug #2391)', () => {
     assert.strictEqual(out03.phase_req_ids, out3.phase_req_ids,
       'phase_req_ids must be identical regardless of padding');
   });
+
+  // ── #904: branch_name must use normalized (stripped + zero-padded) phase number ──
+  // When project_code is set (e.g. "CK") the phase directory is prefixed:
+  // "CK-01-foundation". extractPhaseToken returns "CK-01" as phase_number.
+  // branch_name must call normalizePhaseName so it strips the prefix and zero-pads,
+  // producing "gsd/phase-01-foundation" rather than "gsd/phase-CK-01-foundation".
+  test('branch_name uses normalized phase number when project_code prefixes phase dir (#904)', () => {
+    seedPhase(tmpDir, 'CK-01-foundation', {
+      'CK-01-01-PLAN.md': '# Plan',
+    });
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'config.json'),
+      JSON.stringify({
+        project_code: 'CK',
+        git: {
+          branching_strategy: 'phase',
+          phase_branch_template: 'gsd/phase-{phase}-{slug}',
+        },
+      }, null, 2)
+    );
+
+    const result = runGsdTools('init execute-phase 1', tmpDir);
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const output = JSON.parse(result.output);
+    // branch_name must use the normalized phase number, not the raw "CK-01" token
+    assert.strictEqual(output.branch_name, 'gsd/phase-01-foundation',
+      'branch_name must use normalized phase number (strip project_code prefix, zero-pad), not raw phase_number');
+  });
 });
 
 // ─────────────────────────────────────────────────────────────────────────────