The roles are separate
A physical SIM identifies a mobile subscription. The phone provides the hardware, operating system and supported radio bands. Moving a card does not copy photographs, applications or every contact. Back up the handset independently.
Before moving a card
Check SIM size, device lock status and support for current UK voice services. An old phone can accept a card yet lack compatible voice over 4G. Follow the manufacturer’s instructions and avoid cutting a card by hand.
After insertion
Check calls, messages and mobile data independently. On a dual-SIM phone, select the intended line for each function. If calls work but data does not, review the provider’s configuration guidance rather than guessing access-point settings.
Replacement is an account action
A lost or damaged SIM usually needs a provider-authorised replacement. Report theft promptly and ask the network to secure the line. Do not share replacement codes with callers claiming to be technical staff.
Before you act
Confirm current details directly with the official provider. Our information is independent, general and free of a guidance fee. We do not sell or arrange services.
The official reading list