WhatsApp error 131031: Account has been locked

Code 131031 means the WhatsApp Business Account is locked. Meta gives two distinct reasons in a single message: either the account was restricted or disabled for a policy violation, or the platform could not verify data in your request against what is stored on the account, with the example of an incorrect two-step verification PIN. Those are very different situations that share a code, so the first task is to work out which one you are in.

If the lock follows a registration or PIN change call, the verification failure reading is likely and the account may be temporarily locked after repeated wrong PINs. If it appears on ordinary sends with no registration activity, it is an integrity action similar to 368, and Business Manager's Account Quality page will explain it.

Meta suggests the Health Status API as an additional source, which can show per-node status for the app, WABA, and phone number and often names the blocking reason.

Store the two-step verification PIN in a secrets manager alongside the token so automated registration never guesses, and rate-limit registration attempts on your side. For the policy side, monitor quality ratings and Account Quality alerts routinely so restrictions are anticipated, and keep opt-in evidence ready for any appeal. Registration-side lockouts have their own ladder - 133005, then 133008 - described in the registration troubleshooting guide.