«The approval key is no longer valid.» (phone)

Symptom

When approving, the phone shows «The approval key is no longer valid. Add this account again.» The app offers «Remove the account from this phone».

Cause

The approval key is protected by the phone's biometrics and screen lock. Android permanently invalidates it when you:

• turn off the screen lock (without a lock, no protected key survives);
• your organization requires biometrics only to approve, and you add a new fingerprint or face, or reset biometric data.

The second case is a protection: it stops someone who adds their own fingerprint to the phone from approving on your behalf. When the organization accepts biometrics or PIN, adding a fingerprint does not invalidate the key.

Fix

1. On the error screen, choose «Remove the account from this phone» and confirm.
2. Sign in to the console with your passkey or another phone.
3. Under «My phones», remove this phone's old entry, if it still appears.
4. Link the account again; see Link your phone.

If this was your only phone and you have no passkey, use your recovery codes or ask your helpdesk for help.

When to escalate

If you did not change biometrics or the screen lock, someone may have tampered with the phone: tell your organization's security team.