The new provider coordinates the move of the telephone number; the old SIM is deactivated and the number is routed to the new SIM or eSIM.
Before the port date
The temporary number on the new SIM may work until the port. Keep the old service active and do not erase either phone. Confirm that the new line can connect before the number is moved.
During the change
- The old SIM may lose service.
- The new SIM may briefly show its temporary number.
- Incoming calls, outgoing caller ID, SMS and data can update separately.
- Restarting the phone after the provider confirms completion can refresh registration.
- Apps tied to the number may need time or re-verification.
What does not move automatically
PAYG credit, voicemail messages, account history, add-ons and device-finance agreements do not automatically travel with the telephone number. Check the old account and final bill separately.
Recognise a split port
If outgoing calls show the right number but incoming calls reach the old SIM, or SMS work in only one direction, the routing is incomplete. Do not repeatedly delete eSIMs or reset the phone; report exact examples to the new provider.
After completion
Verify calls, SMS, data, voicemail, Wi‑Fi Calling and important account codes. Keep the old SIM until the final bill and old account status are confirmed, then destroy or recycle it securely.
Messaging apps can show stale information
iMessage, FaceTime and some Android messaging features can retain the temporary number or need re-registration after the port. First confirm ordinary calls and SMS, then review the app’s registered numbers.
Do not delete accounts or erase the phone to correct a display issue. Give routing time to settle and follow the platform’s official number-registration steps.
A practical proof before relying on the result
Expect a staged change rather than one clean switch. The new SIM may first show a temporary number, and inbound routing can lag behind outbound service. Keep a written record of which number each line displays and avoid updating contacts or security accounts until the final number works in both directions.
- Test incoming and outgoing calls from another network.
- Check bank and authenticator SMS only after ordinary SMS is stable.
- Retain the old SIM until the new provider confirms completion.
Official sources
Facts checked: 25 July 2026. Coverage, device support, plan rules and menu paths can change. Recheck your exact phone, software version, network and plan before acting.
