A STAC closes the old mobile service as part of a switch without transferring its number; the new provider’s number remains your number.
PAC or STAC?
| Your intention | Use |
|---|---|
| Keep the old number on the new network | PAC |
| Use the new provider’s new number and close the old service | STAC |
| Keep both services | Neither code; arrange the new service separately and cancel only when appropriate |
| Change tariff within the same provider | Ask for an internal migration |
Request a STAC
- Text STAC to 75075 from the service being closed, or request it through the provider’s official route.
- Read the returned contract and charge information.
- Record the code and expiry date.
- Give the code only to the new provider.
Check every account tied to the old number
- Banking and card-security messages
- Authenticator recovery and account recovery
- Government, NHS and work accounts
- WhatsApp or other messaging registrations
- Delivery, school and emergency contacts
- Voicemail and any call-diversion settings
Do not assume the number can be recovered
After the old service closes, the number may eventually be recycled. Treat the decision as permanent. Change important accounts before submitting the STAC, and keep recovery codes somewhere that does not depend on either phone number.
Final bill and separate agreements
The code closes the relevant mobile service, but it may not end handset finance, insurance or another line on a multi-line account. Check the final bill and leave the Direct Debit active until the provider confirms the balance is settled.
When the change is genuinely complete
A STAC closes the old service without moving its number. Before giving it to the new provider, list every account, contact and recovery method that still uses the old number. The old line should remain available until the new service works and the decision to abandon the number is genuinely final.
- Check banking, email, messaging and delivery accounts for the old number.
- Save the code, issue date and provider confirmation.
- Review the final bill and any separate device finance.
Official sources
Facts checked: 25 July 2026. Rules, plan features and menu paths can change. Recheck the current terms for your exact provider, plan and device before acting.
