# E15019 — WhatsAppSenderNotFound

The from number is not a WhatsApp sender this workspace can send from.

- **HTTP status**: `422`
- **Type**: `validation_error`
- **Name**: `WhatsAppSenderNotFound`

## What to do

Use a business phone number registered to this workspace. Check the number is in E.164 format and that its WhatsApp registration completed.

## Related

- [E15xxx — WhatsApp sending & delivery](/docs/api/errors/E15xxx): every code in this range
- [Errors](/docs/api/errors): the full wire contract, status mapping, and error catalog
- [Error handling](/docs/guides/errors): branching on `type` and `code`, validation details, and `vendor_code`