# SMS Do not contact

Add or import SMS suppression numbers, inspect activity, and manage reviewed release.

## Where to find it

Open **Do not contact** in the SMS workflow.

Address: `/account/sms/dnc`.

## Block numbers

1. Enter numbers with a leading **+** and country code, one per line, or upload a one-column CSV. The optional header is **phone_number**.
2. Keep the list to at most 500 numbers and the CSV under 32 KB.
3. Enter **List source** and **Reason** so the restriction has a reviewable basis.
4. Choose **Review numbers** and correct invalid rows; invalid rows prevent the whole save.
5. Review the intended count and choose **Block N numbers**.

Check the masked lookup and recent activity after saving. The restriction applies across the customer's Topline SMS apps and numbers. Messages already handed to the provider cannot be recalled.

## Review a release

An authorized reviewer uses **Review release**, enters the full number and review reason, and confirms the intended removal. Releasing the SMS restriction does not grant consent, override a provider opt-out, or restart canceled messages. Imports, new consent records, and START replies do not automatically clear a Do not contact restriction.

## Recovery

Correct malformed or oversized input in the same review flow and retry. Do not interpret a failed lookup as an absent restriction, or re-add the number through another app to bypass it.

## Related guides

- [SMS setup](/docs/sms-setup)
- [Messaging agreement](/docs/sms-agreement)