not_on_whatsapp — Number is not on WhatsApp
What the API returns
{
"error": {
"code": "not_on_whatsapp",
"message": "This number is not registered on WhatsApp.",
"request_id": "req_01JRQ8F4X9N2K7YB3C5V6W8H0T"
}
}Every Wapito error is this one envelope. Branch on code, which is stable; message is written for people and can be reworded; details appears only when there is something specific to say; request_id is what to quote to support.
What it means
not_on_whatsapp is an HTTP 404 error from the Wapito WhatsApp API: number is not on WhatsApp. The response message reads “This number is not registered on WhatsApp.” It is not retryable: the same request fails again until you change it. 3 endpoints can raise it, GET /contacts/{id}/exists among them.
Why it happens
The number is syntactically valid but no WhatsApp account is registered against it. This is the normal answer for a landline, a freshly recycled mobile number, a number that only uses WhatsApp Business under a different line, or a typo that happens to be a plausible number. It is a fact about the world rather than a bug, so treat it as data to record against the contact and not as a failure to retry.
How to fix not_on_whatsapp
Store the result against the contact so the same number is not checked again on every run.
If the number came from a form, ask the person to confirm it - a single wrong digit produces exactly this answer.
Do not loop retries over a list of unknown numbers; repeated checking of numbers that are not registered is one of the fastest ways to attract a ban.
Endpoints that raise it
Where you will meet it
- Check Number
Feature guide
Retry guidance
Do not retry as sent
The same request fails the same way until something changes: the body, the credential, the recipient or the state of the channel. Keep it off every retry loop, fix the cause above, and send a corrected request once.
Frequently asked questions
Can a number come back as not registered and still receive messages?
No. If WhatsApp says the number is not registered then there is no account to deliver to, and a send would fail as well. What can change is time: people join WhatsApp, and a number checked months ago may be registered now, so re-check on a slow schedule rather than in a tight loop.
Is bulk checking safe?
It is the single most ban-sensitive thing an unofficial API does, because checking thousands of numbers you have no relationship with looks exactly like list harvesting. Wapito meters checks per plan for that reason. Spread them out, check only numbers you actually intend to contact, and keep the results.
Related
Try it on your own number
Create a channel, link a WhatsApp number by QR or pairing code, and call the API in a couple of minutes. The Sandbox plan is free and needs no card.