---
title: workspace.locked_to_platform_numbers
description: >-
  This workspace already buys its numbers from Sautikit and cannot connect a SIP
  trunk.
summary: >-
  Returned by PUT /v1/sip-trunk and POST /v1/numbers/byo when the workspace
  already claimed a Sautikit number. The buy-or-bring choice is permanent — use
  a new workspace to bring your own trunk.
date: 2026-08-06T00:00:00.000Z
type: error
---


## Summary

`workspace.locked_to_platform_numbers` means the workspace has already committed to buying its numbers from Sautikit, so it cannot also connect its own SIP trunk or register a customer-owned number against one.

## Cause

Every workspace makes a one-time, permanent choice: buy numbers from Sautikit, or bring your own carrier trunk. The two paths are mutually exclusive because rating, rental billing and support each treat a number as either fully ours (rented, priced by series, billed monthly) or fully yours (your carrier, priced per minute, no rent) — mixing the two on one workspace would put an implicit "which kind is this?" branch on every operation.

The lock is set the first time a platform number is successfully claimed (`POST /v1/numbers/{id}/claim`). Once set, both `PUT /v1/sip-trunk` and `POST /v1/numbers/byo` check it and refuse, regardless of whether the trunk or number you are submitting would otherwise be valid — the second endpoint hits the same lock because attaching a customer-owned number is itself a step in bringing your own trunk.

## Resolution

If you want to use your own SIP trunk, create a new workspace for it — the lock is per workspace, not per account. If this workspace was locked to platform numbers by mistake (e.g. a trial number was claimed before you intended to bring your own trunk), release every number first and ask support to reset the workspace's mode; there is no self-service way to reverse the lock once numbers are attached.

```bash
curl -X DELETE "https://api.sautikit.com/v1/numbers/{id}" \
  -H "Authorization: Bearer $SAUTIKIT_API_KEY"
```

## Example response

```json
{
  "error": {
    "code": "workspace.locked_to_platform_numbers",
    "message": "this workspace buys its numbers from Sautikit, so a SIP trunk cannot be connected",
    "request_id": "req_01900000abc"
  }
}
```

## Next steps

- [Numbers concepts — the permanent buy-or-bring choice](/developers/concepts/numbers#bring-your-own-sip-trunk)
- [`workspace.locked_to_byoc`](/developers/errors/workspace.locked_to_byoc) — the mirror-image error on the other side of the same lock