Yes, you can usually put your SIM card in another phone and keep your number. It works when the new phone is unlocked, takes the same SIM size and supports your carrier's network. Three things can stop it: a phone locked to another carrier, a phone with no SIM tray at all (eSIM only), or a phone that doesn't work on your carrier's network. This guide shows how to check each one, what moves with your SIM and what doesn't, and how to move an eSIM instead.
Will my SIM card work in another phone?
Your SIM card holds your line, so your number and plan go wherever the SIM goes. Before you swap, check these four things:
- The phone is unlocked, or locked to the same carrier as your SIM.
- The SIM fits. The new phone takes the same size of SIM card.
- The phone works on your carrier's network, including support for calls over 4G (VoLTE) where your carrier needs it.
- The phone has a SIM tray. Some new phones only take an eSIM.
If all four are fine, the swap takes a minute. Turn off both phones, move the SIM, turn the new phone on and enter your SIM PIN if asked. Then make a test call and send a text to check that everything works.
Can you put any SIM card in any phone?
Not quite. SIM cards are interchangeable between phones as long as the size matches and the phone is unlocked. You can put any SIM card in an unlocked phone that takes that size, but it only works if the phone also supports the carrier's network (see below). There are three common SIM sizes:
- Nano-SIM: the smallest card, used by almost all current smartphones.
- Micro-SIM: a bit bigger, found in older phones.
- Standard (mini) SIM: the largest, used in very old phones and some other devices.
Many carriers ship "multi-size" SIMs that you pop out to the size you need. A smaller SIM can go into a bigger slot with an adapter, but a bigger SIM won't fit a smaller tray. Ask your carrier for a new SIM rather than cutting one. Only use the tray that came with your phone, because trays don't fit other models (Apple: Remove or switch the SIM card in your iPhone). Learn more about the different types of SIM cards.
Network compatibility
An unlocked phone isn't always a compatible phone. A phone made for another region may miss some of the frequency bands your carrier uses. Many carriers have also switched off 3G, so a phone needs VoLTE (calls over 4G or 5G) to make normal calls on their network. Some carriers only allow calls on phones they have approved. Most carriers have a compatibility checker on their website: enter your phone's IMEI, which you can see by dialling *#06#.
What happens if you put a SIM card in a locked phone?
Nothing harmful. The phone simply refuses the SIM:
- An iPhone shows a message such as "The SIM card inserted in this iPhone does not appear to be supported" (Apple: Unlock your iPhone for a different carrier).
- Many Android phones show "SIM not supported" or ask for a network unlock code.
- You get no service, so no calls, texts or mobile data with that SIM.
Your SIM card is not damaged. Put it back in your old phone and it works as before. Don't try to guess an unlock code. Only the carrier the phone is locked to can unlock it. See what it means if a phone is carrier-locked.
How to check if your phone is unlocked
- iPhone: open Settings > General > About and look at Carrier Lock (called Network Provider Lock in some countries). "No SIM restrictions" means the iPhone is unlocked (Apple Support).
- Android: there is no single menu that works on every brand. The easiest test is to insert a SIM from another carrier. If it connects and you can make a call, the phone is unlocked. You can also ask your carrier.
Unlocking rules depend on the country
- UK: mobile companies can't sell locked phones since 17 December 2021 (Ofcom).
- Canada: new phones must be sold unlocked, and carriers must unlock older ones for free on request (CRTC).
- US: there is no single deadline for all carriers. Each carrier sets its own unlocking policy, usually once the phone is paid off and has been active for a while.
- EU: the rules vary by country. Ask your carrier.
Read our guide on how to unlock your phone.
What happens when you put your SIM card in another phone?
Your SIM carries your line, not your phone's content. Here is what moves with it and what doesn't:
- Phone number and plan: move with the SIM. Your SIM PIN moves with it too.
- Contacts: only contacts saved on the SIM itself move. iPhones don't store contacts on the SIM, but you can import SIM contacts in Settings > Apps > Contacts > Import SIM Contacts (Apple Support). Contacts synced with iCloud or your Google account appear once you sign in on the new phone.
- Text messages, photos and apps: stay on the old phone. Use your phone's transfer tool or a backup to move them.
- WhatsApp: your account is linked to your phone number. Put your SIM in the new phone and register with the same number. To keep your chats, use WhatsApp's chat transfer or a backup (WhatsApp Help Center).
- iMessage: moving from an iPhone to an Android phone? Turn off iMessage first, or deregister your number with Apple, so you still get texts from iPhone users.
What if the new phone has no SIM tray?
Then your physical SIM card won't go in at all. A growing number of phones are eSIM only:
- All iPhone 14 and later models bought in the US have no SIM tray (Apple Support).
- iPhone 17 Pro and iPhone 17 Pro Max are eSIM only in Bahrain, Canada, Guam, Japan, Kuwait, Mexico, Oman, Qatar, Saudi Arabia, the UAE, the US and the US Virgin Islands (Apple Newsroom).
- iPhone Air and iPhone Duo are eSIM only in every country (Apple: iPhone Air tech specs).
- Some newer Android phones sold in the US also skip the SIM tray.
Not sure about your model? Check its tech specs for the country where you bought it. If your new phone is eSIM only, ask your carrier to move your line to an eSIM. Many carriers can convert a physical SIM to an eSIM, often from the phone's settings. See how to switch from a physical SIM to an eSIM.
Taking an eSIM-only phone to Europe? The My European eSIM from Bouygues Telecom installs before you fly and gives you data plus a French number for calls and texts in 46 countries.
How to move an eSIM to a new phone
An eSIM can't be taken out, so you move it digitally. Your carrier needs to support the method you use.
iPhone to iPhone: eSIM Quick Transfer
- Keep both iPhones close together with Bluetooth on, and sign in to both with the same Apple Account.
- On the new iPhone, open Settings > Cellular (called Mobile Service in some countries) and tap Set Up Cellular or Add eSIM.
- Choose the line to transfer, or tap Transfer From Nearby iPhone.
- Follow the steps on your old iPhone and wait for the line to activate.
The line stops working on your old iPhone once it activates on the new one. You can also do this during setup of a new iPhone (Apple: Set up eSIM on iPhone).
Android to Android
On many Android phones you can transfer a SIM or eSIM while setting up the new phone, or later in Settings > Network & internet > SIMs > Add SIM > Transfer SIM from another device (Pixel Phone Help). Samsung phones have a similar option in SIM manager. Menu names vary by brand. If the transfer isn't offered, your carrier can send you a new eSIM QR code.
Between iPhone and Android
Some carriers support direct transfers between iPhone and Android. If yours doesn't, ask it for a new eSIM. Read more in our guide on how to transfer an eSIM. A travel eSIM doesn't always support transfers, so check with the provider before you delete it from your old phone.
Travelling with an eSIM-only or locked phone?
With an eSIM-only phone, you can't pop in a local SIM card when you land. A travel eSIM solves this: you install it before you leave and it connects when you arrive. It works on any unlocked phone that supports eSIM. Check yours in our list of eSIM supported phones.
If your phone is locked, a travel eSIM or a local SIM won't work either. Ask your carrier to unlock it a few days before your trip. On a dual SIM phone you can keep your home line on for calls and texts while the travel eSIM handles your data.
Data-only eSIMs that you install before you leave · Mexico · Canada · Asia · Find the eSIM for your destination
FAQs
Can I buy a new phone and put my SIM card in it?
Yes, if the phone is unlocked (or from your carrier), takes your SIM size and works on your carrier's network. If it is eSIM only, ask your carrier to move your line to an eSIM.
Are all new phones unlocked?
No. Phones bought SIM-free are normally unlocked, but phones from a carrier can be locked, especially in the US. In the UK and Canada, carriers have to sell them unlocked. Always check before you buy.
Can I put a new SIM card in a locked phone?
It will fit, but it only works if the SIM is from the carrier the phone is locked to. A SIM from any other carrier shows an error such as "SIM not supported" and gets no service. Ask the carrier that locked the phone to unlock it first.
Can I put any SIM card in an unlocked phone?
Yes, if it's the right size and the phone supports that carrier's network. That's the point of an unlocked phone: you can switch carriers, or use a local SIM or travel eSIM abroad.
Can I activate a SIM card on a different phone?
Yes. Your line is on the SIM, not tied to one phone, so it activates in any compatible unlocked phone. Some carriers ask you to register the new phone's IMEI, so check their app or website.
Will I lose my number if I put my SIM in another phone?
No. Your number stays with the SIM card. Your old phone simply has no service until you put a SIM back in.
Can any SIM card work in any phone?
No. The phone must be unlocked, fit the SIM size, support the carrier's network and have a SIM tray. A carrier-locked phone only accepts SIMs from its own carrier.