The fastest way to move your cellular data is through iCloud or a direct device-to-device transfer

When you set up a new iPhone, Apple gives you two main paths to move your cellular data — the information your phone stores about your carrier account, phone number, and service settings. The simplest method is Quick Start, which transfers data directly from your old iPhone to your new one over Wi-Fi while you're holding them side by side. If you don't have your old phone anymore, iCloud backup restores your cellular data along with everything else on your account. Both methods move your phone number, carrier settings, and eSIM information (if your carrier uses it) without you having to contact your carrier.

The process takes 15 to 30 minutes for Quick Start, or about the same time to restore from iCloud after you sign in. You don't need to do anything with your old phone's carrier account — your new iPhone becomes the active device on your line automatically once the transfer completes and you connect to cellular service.

Key Takeaways

  • Quick Start transfers your phone number, carrier settings, and eSIM data directly from your old iPhone to your new one without involving your carrier.
  • iCloud backup restores cellular data along with all your other phone information if you don't have your old device available.
  • Both methods work for physical SIM cards and eSIMs, though eSIM transfers are faster because they don't require a physical card swap.
  • After transfer completes, your new iPhone becomes active on your carrier's network automatically — you don't need to call your carrier unless something fails.
  • If the transfer doesn't work, your carrier can manually move your phone number and service to the new phone using your account information.

Using Quick Start to transfer data between iPhones

Quick Start is the fastest method if you have both phones. Turn on your new iPhone and hold it near your old one. Your old iPhone will show a setup screen asking if you want to use Quick Start to set up the new device. Tap "Continue" on the old phone, then point your new iPhone's camera at the animation that appears on the old phone's screen. This pairs the devices over a find connection.

After pairing, your old iPhone will ask you to enter your Apple ID password on the new phone. Once you do, the transfer begins — your cellular data, eSIM information, phone number, and carrier settings move over automatically. You'll see a progress bar on both phones. Don't interrupt this process or move the phones far apart, even though they're using Wi-Fi rather than Bluetooth. The transfer usually completes in 15 to 30 minutes depending on how much data you're moving.

When it finishes, your new iPhone is ready to use on your carrier's network. Your old iPhone will show a message that the setup is complete. You can then back up or reset the old phone if you're selling it or giving it away.

Restoring cellular data from iCloud backup

If you don't have your old iPhone, you can restore from an iCloud backup that contains your cellular data. During setup on your new phone, you'll reach a screen asking how you want to set up your iPhone. Choose "Restore from iCloud Backup" instead of Quick Start. Sign in with your Apple ID, then select the backup you want to restore from — usually the most recent one.

iCloud will restore your phone number, carrier settings, eSIM information, and all your other data (apps, photos, messages, contacts) from that backup. The process takes 15 to 45 minutes depending on your Wi-Fi speed and how much data is in the backup. Your new iPhone must stay connected to Wi-Fi and power during the restore.

Once the restore finishes, your new iPhone automatically connects to your carrier's network using the restored cellular settings. If you're using an eSIM, it activates on the new phone without any additional steps. If you're using a physical SIM card, you'll need to insert the SIM from your old phone or request a new one from your carrier.

Physical SIM cards versus eSIM transfers

Your carrier uses one of two methods to identify your phone on their network: a physical SIM card (a small chip you insert into a slot) or an eSIM (digital information stored in your phone's software). The transfer method depends on which one you have.

If you have a physical SIM card, you can move it directly from your old iPhone to your new one after the data transfer completes. Power off both phones, remove the SIM from the old phone using the ejector tool that came with it, insert it into the new phone, and power on. Your new phone will recognize the SIM and connect to your carrier's network. You don't need to contact your carrier unless the SIM doesn't work in the new phone.

If you have an eSIM, the transfer happens automatically during Quick Start or iCloud restore — there's no physical card to move. The eSIM data transfers to your new phone as part of the backup. After setup completes, your new phone is already active on your carrier's network. eSIM transfers are faster and don't require any physical steps, which is why many carriers are moving toward eSIM-only service.

What to do if the transfer fails

If Quick Start doesn't complete or your new iPhone doesn't connect to cellular service after the transfer, the most common causes are Wi-Fi interruption, a problem with your eSIM, or a carrier account issue. First, check that both phones stayed connected to the same Wi-Fi network during the transfer. If the connection dropped, you may need to start Quick Start again.

If you're using an eSIM and it didn't transfer, restart your new iPhone and wait a few minutes for it to reconnect to your carrier's network. Sometimes the eSIM set up takes longer than expected. If it still doesn't work after a restart, contact your carrier — they can resend the eSIM set up to your new phone or switch you to a physical SIM card if needed.

If you're using a physical SIM card, make sure it's fully inserted into the new phone and the phone is powered on. Try restarting the new iPhone. If you still see "No Service," the SIM may be damaged or your carrier may need to set up it on the new phone. Call your carrier's customer service number (usually on the back of your SIM card or your bill) and tell them you've switched to a new iPhone — they can set up the SIM or send you a replacement.

Transferring data when switching carriers

If you're moving to a new carrier, the process is different because your phone number and service settings belong to your old carrier. You'll need to port your phone number to the new carrier before or during the iPhone transfer. Contact your new carrier and ask them to port your number from your old carrier — they'll handle the carrier-side transfer, which usually takes 24 hours.

Once the port is complete, your new carrier will send you a new SIM card or eSIM set up. Set up your new iPhone using Quick Start or iCloud restore as usual, but when you reach the SIM setup screen, use the new SIM or eSIM from your new carrier instead of your old one. Your new iPhone will then connect to your new carrier's network with your ported phone number.

If you're switching carriers and don't have your old phone, you can still port your number — just contact your new carrier with your account information from your old carrier (usually your phone number, account number, and the last four digits of the Social Security number on the account). They'll handle the port while you set up your new iPhone with iCloud restore.

Keeping your old phone active during the transfer

Your old iPhone will continue to work on your carrier's network until you officially deactivate it or your carrier moves your phone number to the new phone. If you're using Quick Start or iCloud restore, your carrier automatically moves your service to the new iPhone once the transfer completes and the new phone connects to cellular service. Your old phone will lose service within a few hours.

If you want to keep your old phone active for a few days (to make sure everything transferred correctly, for example), contact your carrier and ask them to delay moving your service. Some carriers can keep both phones active temporarily, though you'll only be able to use one at a time on your phone number. Others will move your service when ready and can't reverse it, so ask before you set up the new phone if this matters to you.

Frequently Asked Questions

Do I need to contact my carrier to transfer my phone number?

No. Quick Start and iCloud restore both move your phone number and carrier settings automatically. Your carrier's system recognizes the new iPhone as the active device once it connects to their network. You only need to contact your carrier if the transfer fails or if you're switching to a different carrier.

What happens to my old iPhone after the transfer?

Your old iPhone loses cellular service within a few hours once your carrier moves your phone number to the new device. It can still connect to Wi-Fi and use apps that don't need cellular service. You can back it up, reset it, and sell or recycle it. If you want to keep it as a backup phone, you can ask your carrier about adding it to your account as a secondary line.

Can I transfer cellular data if my old iPhone is broken?

Yes. Use iCloud restore instead of Quick Start. As long as you have your Apple ID password and a recent iCloud backup, you can restore your phone number, carrier settings, and eSIM to your new iPhone. If you have a physical SIM card, you'll need to insert it into the new phone after the restore completes.

Will my eSIM transfer if I restore from an old backup?

Yes, if the backup is from an iPhone that had the eSIM active. iCloud backs up your eSIM information along with everything else. When you restore to your new iPhone, the eSIM activates automatically. If the eSIM doesn't set up after restore, restart your new iPhone and wait a few minutes, or contact your carrier to resend the set up.

What if my new iPhone says "No Service" after the transfer?

Restart your new iPhone and wait a few minutes for it to reconnect to your carrier's network. If you're using a physical SIM, make sure it's fully inserted. If you're using an eSIM, check that it transferred during setup — if not, contact your carrier and ask them to resend the eSIM set up. If the problem persists after a restart, call your carrier's customer service.