Key Takeaways
- A physical SIM card moves directly from your old iPhone to your new one, and your number transfers immediately once the new phone recognizes it.
- eSIM transfers happen through your carrier's app or settings menu and don't require a physical card, though the process varies by carrier.
- Porting your number to a new carrier requires contacting the new carrier with your account details and takes between a few hours and one business day.
- Your phone number is separate from your data — transferring the number doesn't move your contacts, photos, or messages unless you back those up separately.
- Most carriers charge nothing to transfer an existing number to a new phone on the same account, but switching carriers may involve early termination fees on your old contract.
Using Your Existing SIM Card
If your current iPhone has a physical SIM card, the simplest transfer is to remove it and insert it into your new iPhone. Power off both phones, then use the SIM ejector tool (a small pin that came with your phone or carrier kit) to open the SIM tray on your old iPhone. Remove the card carefully and insert it into the SIM tray on your new phone in the same orientation.
Once you power on the new iPhone, it will recognize the SIM card within a few minutes. Your phone number is now active on the new device. You should see a signal indicator appear in the status bar. Text a friend or call your voicemail to confirm the number is working. This method works whether you're upgrading within the same carrier or moving to a new phone on the same account.
The SIM card itself holds your phone number and carrier information, so moving it is the most direct route. However, this only transfers your ability to make calls and send texts — your contacts, photos, messages, and apps remain on your old phone unless you back them up through iCloud or another method first.
Transferring an eSIM to Your New iPhone
Many newer iPhones and carriers now use eSIM, a digital SIM stored in your phone's software rather than a physical card. If your carrier supports eSIM, you can transfer your number without touching any hardware. The exact steps depend on your carrier, but most follow a similar path: open Settings on your new iPhone, go to Cellular, and select "Add Cellular Plan."
Your carrier will either send you a QR code via email or text that you scan with your new iPhone, or they'll let you log into their app to transfer the plan directly. Some carriers, like Verizon and AT&T, let you do this through their mobile app. Others require you to call customer service or visit a store. The transfer usually completes within minutes, though some carriers take up to a few hours to activate the eSIM on their backend.
If you're keeping both phones temporarily, you can often keep the eSIM active on your old iPhone while setting up the new one, then remove it from the old phone later. Check with your carrier about their specific eSIM transfer policy, as some require you to deactivate the old phone first.
Porting Your Number to a New Carrier
If you're switching to a different carrier, you'll need to port your number rather than simply moving a SIM card. Contact your new carrier and tell them you want to bring your existing number. They'll ask for your account number, PIN, and billing zip code from your current carrier — this information proves you own the number.
Your new carrier will submit a port request to your current carrier, which has up to one business day to process it. During this window, your old carrier may send you a confirmation text or email asking you to approve the transfer. Once approved, your number switches to the new carrier's network, usually within a few hours. You'll need a new SIM card from your new carrier, either physical or eSIM, to activate the number on your new iPhone.
Some carriers charge an early termination fee if you're breaking a contract with your old provider, but porting the number itself is free. Ask your new carrier if they offer any credits or promotions to offset this cost. During the port process, you may have a brief window (usually under an hour) where calls and texts don't work on either network — this is normal and resolves once the port completes.
What Happens to Your Data During a Number Transfer
Moving your phone number does not move your contacts, messages, photos, or apps. Your number is tied to your carrier's account and SIM, while your data lives in your phone's storage or iCloud. If you want to keep your messages and contacts on your new iPhone, you need to back them up separately before transferring the number.
The easiest method is to use iCloud. On your old iPhone, go to Settings, tap your name, select iCloud, and turn on Contacts, Messages, and Photos. Then sign into the same iCloud account on your new iPhone and let it sync. Alternatively, you can connect your old iPhone to a computer and create an encrypted backup in Finder (Mac) or iTunes (Windows), then restore that backup on your new phone after the number transfer is complete.
If you're switching carriers and want to keep your old phone as a backup or for reference, your old number will stop working once the port completes, but the phone itself will still have all your old data stored locally. You can access it over WiFi without an active phone number.
Troubleshooting When Your Number Doesn't Transfer
If your SIM card is inserted but your number isn't showing up, restart your new iPhone. Go to Settings, Cellular, and check that Cellular Data is turned on. If you see "No Service" after 10 minutes, remove the SIM card, inspect it for dirt or damage, and reinsert it. If the card is visibly cracked or bent, contact your carrier for a replacement.
For eSIM transfers that aren't working, check that you're connected to WiFi and that your carrier's app is up to date. Some carriers require you to deactivate the eSIM on your old phone before activating it on the new one. If the QR code scan fails, try entering the activation code manually — your carrier can provide this if the QR method doesn't work.
If you're porting to a new carrier and your number hasn't switched after 24 hours, contact the new carrier's customer service. Provide them with the port request reference number (they should have given you this when you started the process). Delays sometimes happen if the old carrier didn't receive or process the request correctly, and customer service can resubmit it or escalate the issue.
Keeping Your Old Phone Active While You Set Up the New One
You don't have to transfer your number immediately. If you want to keep your old iPhone active while you set up the new one, you can wait a few days before moving the SIM card or porting your number. This gives you time to back up your data, restore it on the new phone, and make sure everything is working before the old phone loses service.
If you're using eSIM, you can often keep the plan active on both phones for a short period. Contact your carrier to ask how long they allow this — most give you 24 to 48 hours to deactivate the old phone. After that window, the eSIM on the old phone will stop working to prevent duplicate charges.
For physical SIM cards, once you remove the card from your old phone, that phone loses service immediately. If you think you'll need to reference information on the old phone, make sure you've backed up everything to iCloud or your computer first.
Frequently Asked Questions
Can I transfer my number if I'm still under contract with my old carrier?
Yes, you can port your number to a new carrier even if you're under contract. However, your old carrier may charge an early termination fee, which is usually between $150 and $350 depending on how much time is left on your contract. Ask your new carrier if they offer any credits or promotions to help cover this cost.
What if my new iPhone doesn't have a SIM card slot?
Newer iPhones (iPhone 14 and later in some regions) use eSIM only and don't have a physical SIM slot. If you're upgrading to one of these models, you'll need to transfer your number via eSIM through your carrier's app or website. Contact your carrier to confirm they support eSIM before you purchase the phone.
How long does it take for my number to work on the new iPhone?
With a physical SIM card, your number is usually active within a few minutes of powering on the new phone. With eSIM, activation typically takes 15 minutes to a few hours depending on your carrier. If you're porting to a new carrier, the entire process takes up to one business day, though it's often faster.
Will I lose my text messages when I transfer my number?
Your text messages stay on your old iPhone unless you back them up. Use iCloud backup or create an encrypted backup on your computer before transferring your number. Then restore that backup on your new iPhone to bring over your messages, contacts, and other data.
Do I need to tell my old carrier I'm leaving before I port my number?
You don't have to notify them in advance, but it's a good idea to check your contract for any early termination fees. When you contact your new carrier to start the port, they'll handle the request with your old carrier. Your old carrier will send you a confirmation, and you can approve or cancel the port at that point.