Help & Support


Changing your SIM

If you get a new SIM card, you might want to swap your existing number onto it. We call this SIM swap.

Do you need to change your SIM if you’ve upgraded to a new phone with us?

Is your current SIM the right size for your new phone?

If you’ve got a new SIM that’s the same size as your current SIM card, you don’t need to SIM swap. Just take the new SIM out of your phone and put your current one in. Throw the new one away and then just start to use your new phone as normal.

Is your current SIM the wrong size for your new phone?

If your new phone takes a different sized SIM, you’ll need to keep the new SIM in it while you do your SIM swap. From your current SIM card, text SWAP to 23424 and follow the instructions. This will swap your current mobile number onto your new SIM.

If you’ve changed your phone or SIM card

Maybe you got a new phone from a family member or you’ve bought another phone from somewhere else?

If your new phone needs a different sized SIM card from your current one, please contact us to get a new SIM. We’ll send you a replacement SIM which will already have your number active. If you need to unlock your phone, please ask your current network for an unlock code.

If your old SIM was lost or damaged and you don’t have your old SIM card

If your phone or SIM has been lost or stolen, please call us straight away on 0345 301 4455. If you don’t have access to another phone, you can contact us online or via Facebook or Twitter.

> Get more info on lost or stolen

How to change your SIM (SIM swap)

  1. Save your contacts to your phone and back up anything you want to keep (photos, videos etc)
  2. Text SWAP to 23424 from your original SIM card and follow the instructions that we text back
  3. You may have a temporary loss of service during the next few hours as the new SIM activates
  4. Your number will be on your new SIM within 24 hours

If you’re on pay as you go, any credit or bundles will be transferred onto your new SIM.

If you’re a business customer, please contact us.

Other number transfers

Still need help? Or want to transfer your number from pay monthly to pay as you go or the other way round?

Please call us free on 4455 from your Tesco Mobile phone or 0345 301 4455 from another phone.

If you’re a business customer, please call us on 0345 601 2448.