# E15044 — WhatsAppServiceWindowClosed

This conversation's 24-hour customer service window is closed, so only a template message can be sent.

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

## What to do

WhatsApp allows a free-form message only within 24 hours of the contact's most recent message to this number. Send a template instead: list the templates whose status is active, since an unfiltered list also returns draft, pending, rejected, and inactive templates that a send would refuse. A template reaches the contact now and reopens the window for free-form replies once they answer.

## 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`