# E15003 — WhatsAppTemplateParameterMismatch

The message parameters do not match the parameters the template declares.

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

## What to do

The parameters you sent do not match what the template declares. List the template to see the parameters it expects, then send exactly those in order.

Operations that resolve this:

- [List available message templates](/docs/api/reference/list-whats-app-templates)

## 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`