diff --git a/README.md b/README.md
index 4243609..0c7ede9 100644
--- a/README.md
+++ b/README.md
@@ -252,7 +252,7 @@ authmux parallel --install        # Write aliases to shell rc file
 
 Each profile gets its own config directory at `~/.claude-accounts/<name>`. Shell aliases/functions set `CLAUDE_CONFIG_DIR` before launching `claude`, so each instance uses isolated credentials, settings, and history. `authmux parallel --install` writes Bash/Zsh aliases or Fish autoload functions based on `$SHELL`. Login and logout commands bypass Cue so refreshed OAuth tokens are written back to the right account directory. Generated login wrappers use `authmux parallel --login <name> --fresh --require-distinct`, which backs up stale Claude auth first and rejects a login that resolves to another configured profile. Run profiles in separate terminal tabs or tmux panes for true parallel usage.
 
-`authmux parallel --list` warns when two profiles contain the same Claude credentials or the same Claude OAuth account UUID. Those profiles are not independent: logging in or out of one can invalidate the other because Claude sees them as the same account session. Re-run `authmux parallel --login <name> --fresh --require-distinct` and choose a different Anthropic account for any profile that should have its own subscription/session.
+`authmux parallel --list` warns when two profiles contain the same Claude credentials or the same fresh Claude OAuth account UUID. Those profiles are not independent: logging in or out of one can invalidate the other because Claude sees them as the same account session. Re-run `authmux parallel --login <name> --fresh --require-distinct` and choose a different Anthropic account for any profile that should have its own subscription/session. If `.claude.json` is older than the active credentials, Authmux marks it as `claudeAccountState=stale` and does not use that stale UUID for duplicate-account detection.
 
 ### Notes
 
diff --git a/openspec/changes/agent-codex-ignore-stale-claude-account-metadata-2026-06-29-08-52/.openspec.yaml b/openspec/changes/agent-codex-ignore-stale-claude-account-metadata-2026-06-29-08-52/.openspec.yaml
new file mode 100644
index 0000000..34f9314
--- /dev/null
+++ b/openspec/changes/agent-codex-ignore-stale-claude-account-metadata-2026-06-29-08-52/.openspec.yaml
@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2026-06-29
diff --git a/openspec/changes/agent-codex-ignore-stale-claude-account-metadata-2026-06-29-08-52/notes.md b/openspec/changes/agent-codex-ignore-stale-claude-account-metadata-2026-06-29-08-52/notes.md
new file mode 100644
index 0000000..a6e9237
--- /dev/null
+++ b/openspec/changes/agent-codex-ignore-stale-claude-account-metadata-2026-06-29-08-52/notes.md
@@ -0,0 +1,16 @@
+# agent-codex-ignore-stale-claude-account-metadata-2026-06-29-08-52 (minimal / T1)
+
+Branch: `agent/codex/ignore-stale-claude-account-metadata-2026-06-29-08-52`
+
+Ignore stale `.claude.json` OAuth account UUID metadata when newer `.credentials.json` exists, so different credentials are not falsely flagged as duplicate accounts.
+
+## Handoff
+
+- Handoff: change=`agent-codex-ignore-stale-claude-account-metadata-2026-06-29-08-52`; branch=`agent/codex/ignore-stale-claude-account-metadata-2026-06-29-08-52`; scope=`src/commands/parallel.ts src/tests/json-parity.test.ts README.md`; action=`finish stale Claude metadata handling and refresh live build/wrappers after merge`.
+- Copy prompt: Continue `agent-codex-ignore-stale-claude-account-metadata-2026-06-29-08-52` on branch `agent/codex/ignore-stale-claude-account-metadata-2026-06-29-08-52`. Work inside the existing sandbox, review `openspec/changes/agent-codex-ignore-stale-claude-account-metadata-2026-06-29-08-52/notes.md`, continue from the current state instead of creating a new sandbox, and when the work is done run `gx branch finish --branch agent/codex/ignore-stale-claude-account-metadata-2026-06-29-08-52 --base main --via-pr --wait-for-merge --cleanup`.
+
+## Cleanup
+
+- [ ] Run: `gx branch finish --branch agent/codex/ignore-stale-claude-account-metadata-2026-06-29-08-52 --base main --via-pr --wait-for-merge --cleanup`
+- [ ] Record PR URL + `MERGED` state in the completion handoff.
+- [ ] Confirm sandbox worktree is gone (`git worktree list`, `git branch -a`).
diff --git a/src/commands/parallel.ts b/src/commands/parallel.ts
index 16ff2ac..6ce59f3 100644
--- a/src/commands/parallel.ts
+++ b/src/commands/parallel.ts
@@ -36,6 +36,7 @@ interface ParallelProfileEntry {
   skillProfile: string;
   cueProfile: string;
   credentialsPresent: boolean;
+  claudeAccountStateStale: boolean;
   credentialsDuplicateOf?: string;
   claudeAccountDuplicateOf?: string;
 }
@@ -154,18 +155,33 @@ function hashFileIfPresent(file: string): string | undefined {
   return hash.digest("hex");
 }
 
-function readClaudeAccountUuid(name: string): string | undefined {
+function statFileIfPresent(file: string): fs.Stats | undefined {
+  return fs.statSync(file, { throwIfNoEntry: false }) ?? undefined;
+}
+
+function readClaudeAccountUuid(name: string, credentialsMtimeMs?: number): {
+  uuid?: string;
+  stale: boolean;
+} {
   const file = claudeStatePathForProfile(name);
-  if (!fs.existsSync(file)) return undefined;
+  const stateStat = statFileIfPresent(file);
+  if (!stateStat) return { stale: false };
+
+  if (credentialsMtimeMs !== undefined && stateStat.mtimeMs < credentialsMtimeMs) {
+    return { stale: true };
+  }
 
   try {
     const parsed = JSON.parse(fs.readFileSync(file, "utf8")) as {
       oauthAccount?: { accountUuid?: unknown };
     };
     const uuid = parsed.oauthAccount?.accountUuid;
-    return typeof uuid === "string" && uuid.length > 0 ? uuid : undefined;
+    return {
+      uuid: typeof uuid === "string" && uuid.length > 0 ? uuid : undefined,
+      stale: false,
+    };
   } catch {
-    return undefined;
+    return { stale: false };
   }
 }
 
@@ -186,8 +202,10 @@ function buildProfileEntries(profiles = getProfiles()): ParallelProfileEntry[] {
   const seenClaudeAccountUuids = new Map<string, string>();
 
   return profiles.map((p) => {
-    const credentialHash = hashFileIfPresent(credentialsPathForProfile(p));
-    const claudeAccountUuid = readClaudeAccountUuid(p);
+    const credentialsPath = credentialsPathForProfile(p);
+    const credentialsStat = statFileIfPresent(credentialsPath);
+    const credentialHash = credentialsStat ? hashFileIfPresent(credentialsPath) : undefined;
+    const claudeAccount = readClaudeAccountUuid(p, credentialsStat?.mtimeMs);
 
     return {
       name: p,
@@ -195,8 +213,9 @@ function buildProfileEntries(profiles = getProfiles()): ParallelProfileEntry[] {
       skillProfile: readSkillProfile(p) ?? "base",
       cueProfile: readCueProfile(p) ?? readSkillProfile(p) ?? DEFAULT_CUE_PROFILE,
       credentialsPresent: Boolean(credentialHash),
+      claudeAccountStateStale: claudeAccount.stale,
       credentialsDuplicateOf: duplicateOwner(credentialHash, seenCredentialHashes, p),
-      claudeAccountDuplicateOf: duplicateOwner(claudeAccountUuid, seenClaudeAccountUuids, p),
+      claudeAccountDuplicateOf: duplicateOwner(claudeAccount.uuid, seenClaudeAccountUuids, p),
     };
   });
 }
@@ -411,6 +430,7 @@ export default class ClaudeParallel extends Command {
       const duplicateBits = [
         p.credentialsDuplicateOf ? `credentialsDuplicateOf=${p.credentialsDuplicateOf}` : undefined,
         p.claudeAccountDuplicateOf ? `claudeAccountDuplicateOf=${p.claudeAccountDuplicateOf}` : undefined,
+        p.claudeAccountStateStale ? "claudeAccountState=stale" : undefined,
       ].filter(Boolean);
       const duplicateSuffix = duplicateBits.length ? ` ${duplicateBits.join(" ")}` : "";
       this.log(
diff --git a/src/tests/json-parity.test.ts b/src/tests/json-parity.test.ts
index 1f7dc8c..869b486 100644
--- a/src/tests/json-parity.test.ts
+++ b/src/tests/json-parity.test.ts
@@ -240,6 +240,55 @@ test("parallel --list flags duplicate Claude credentials", async () => {
   });
 });
 
+test("parallel --list ignores stale Claude account UUID metadata", async () => {
+  await withSandbox(async (env) => {
+    for (const profile of ["account1", "account2"]) {
+      const added = runCli(["parallel", "--add", profile, "--json"], env);
+      assert.equal(added.status, 0, added.stderr);
+    }
+
+    const accountsDir = path.join(env.HOME as string, ".claude-accounts");
+    const sharedClaudeState = JSON.stringify({
+      oauthAccount: {
+        accountUuid: "same-claude-account",
+      },
+    });
+    const account1Dir = path.join(accountsDir, "account1");
+    const account2Dir = path.join(accountsDir, "account2");
+    await fsp.writeFile(
+      path.join(account1Dir, ".credentials.json"),
+      JSON.stringify({ claudeAiOauth: { accessToken: "account1-token" } }),
+    );
+    await fsp.writeFile(path.join(account1Dir, ".claude.json"), sharedClaudeState);
+    await fsp.writeFile(path.join(account2Dir, ".claude.json"), sharedClaudeState);
+    const staleTime = new Date("2020-01-01T00:00:00Z");
+    await fsp.utimes(path.join(account2Dir, ".claude.json"), staleTime, staleTime);
+    await fsp.writeFile(
+      path.join(account2Dir, ".credentials.json"),
+      JSON.stringify({ claudeAiOauth: { accessToken: "account2-token" } }),
+    );
+
+    const listed = runCli(["parallel", "--list", "--json"], env);
+    assert.equal(listed.status, 0, listed.stderr);
+
+    const parsed = JSON.parse(listed.stdout.trim()) as {
+      ok: true;
+      data: {
+        profiles: Array<{
+          name: string;
+          claudeAccountStateStale: boolean;
+          credentialsDuplicateOf?: string;
+          claudeAccountDuplicateOf?: string;
+        }>;
+      };
+    };
+    const account2 = parsed.data.profiles.find((p) => p.name === "account2");
+    assert.equal(account2?.claudeAccountStateStale, true);
+    assert.equal(account2?.credentialsDuplicateOf, undefined);
+    assert.equal(account2?.claudeAccountDuplicateOf, undefined);
+  });
+});
+
 test("parallel --login can reject duplicate Claude accounts", async () => {
   await withSandbox(async (env) => {
     for (const profile of ["account1", "account2"]) {