What an IMEI number tells you about iPhone locks

An IMEI (International Mobile Equipment Identity) is a 15-digit code unique to every iPhone. It identifies your device to cellular networks worldwide. You can use this number to check whether your iPhone is locked to a specific carrier — meaning it will only work with that carrier's SIM card — or whether it's unlocked and will accept any carrier's SIM.

The check itself is free and takes about five minutes. You'll need the IMEI number, access to a web browser, and a carrier's official unlock checker tool. Apple does not provide a single master tool for this; instead, each major carrier (AT&T, Verizon, T-Mobile, and others) runs its own checker on its website.

This matters because a locked iPhone limits which networks you can use. If you travel internationally, switch carriers, or sell the phone later, an unlocked device is far more valuable and flexible. Checking the IMEI before you buy a used iPhone, or after you request an unlock from your carrier, confirms the actual status rather than taking someone's word for it.

Key Takeaways

  • Your iPhone's IMEI is a 15-digit number you can find by dialing *#06# or in Settings under General > About.
  • Each carrier (AT&T, Verizon, T-Mobile, Sprint) runs its own free IMEI checker on its official website — there is no single Apple tool.
  • A locked iPhone will only accept SIM cards from one carrier; an unlocked iPhone works with any carrier's SIM.
  • The checker tells you the lock status but does not change it; you must contact your carrier directly to request an unlock if the phone is locked.

Finding your iPhone's IMEI number

The fastest way to get your IMEI is to dial it directly into your iPhone's phone app. Open the Phone app, tap the keypad, and type *#06#. Your IMEI will appear on the screen automatically. Do not press call — just type the code and wait a few seconds.

If that method does not work (it occasionally fails on older iOS versions), you can find the IMEI in your Settings. Open Settings, tap General, then tap About. Scroll down until you see the line labeled IMEI. Write down or screenshot the full 15-digit number.

A third option is to check your original iPhone box or receipt. Apple prints the IMEI on the box and on your purchase receipt. If you no longer have the box, the dialing method or Settings route will work just as well.

Checking the lock status with your carrier's tool

Once you have the IMEI, visit your carrier's official website. Do not use a third-party checker — carriers' own tools are free and reliable, while third-party sites sometimes charge fees or misreport results.

AT&T: Go to att.com/deviceunlock. Paste your IMEI into the field and select "Check Unlock Status." The page will tell you whether the device is locked or unlocked within seconds.

Verizon: Visit verizon.com/about/consumer-protections/unlocking-policy. Scroll to the checker tool, enter your IMEI, and submit. Verizon's tool shows lock status immediately.

T-Mobile: Go to t-mobile.com/account/devices/unlock-device. Enter your IMEI and phone number (associated with the account, if you have one). T-Mobile displays the status right away.

Sprint: Visit sprint.com/en/support/solutions/services/check-device-unlock-status.html. Enter your IMEI and follow the prompts. Sprint was acquired by T-Mobile in 2020, so if you see a redirect to T-Mobile's tool, use that instead.

If your carrier is a regional or prepaid provider, search "[Your Carrier Name] IMEI unlock checker" to find their tool. Most major carriers offer one, though smaller providers sometimes require you to call customer service instead.

Understanding the results

The checker will return one of three results: Unlocked, Locked, or Unable to Determine.

If the result is Unlocked, your iPhone will accept SIM cards from any carrier. You can switch to a different network, use an international SIM while traveling, or sell the phone knowing it has no carrier restrictions.

If the result is Locked, your iPhone is tied to that carrier's network. You cannot use a different carrier's SIM card until the carrier unlocks it. Contact the carrier's customer service and request an unlock. Most carriers unlock phones for free if the account is in good standing and the device is paid off. The unlock usually takes 24 to 48 hours to process.

If the result is Unable to Determine, the checker could not reach the carrier's database or the IMEI was not found in their system. This sometimes happens with very new devices, devices purchased outside the US, or if you entered the IMEI incorrectly. Double-check the IMEI and try again in a few hours, or call the carrier directly.

What to do if the iPhone is locked

If the checker shows your iPhone is locked and you want to use a different carrier, contact your current carrier's customer service. Have your IMEI and account information ready. Ask to request an unlock.

Most carriers have standard requirements: the account must be in good standing (no unpaid bills), the device must be fully paid off (not on a payment plan), and the account must have been active for a minimum time (often 40 to 60 days). If you meet these requirements, the carrier will process the unlock request. You do not need to return to a store — it happens remotely.

After the carrier confirms the unlock, your iPhone will receive a notification or you may need to restart it. The lock is then removed and the phone will accept any carrier's SIM card. If you have already purchased a new SIM card from another carrier, insert it and the iPhone should connect to that network within a few minutes.

If the carrier denies your unlock request, ask why. Common reasons are an outstanding balance, an active payment plan, or an account that is too new. Resolve the issue and resubmit the request after the waiting period has passed.

Checking a used iPhone before you buy

If you are considering buying a used iPhone, ask the seller for the IMEI before you complete the purchase. You can then run it through the carrier checker yourself to confirm the lock status. This protects you from buying a locked phone that you cannot use.

Some sellers will not provide the IMEI upfront. In that case, ask to see the iPhone in person and dial *#06# yourself to get the number. If the seller refuses to let you check, that is a red flag — walk away.

Be aware that a locked iPhone is worth less than an unlocked one, even if the hardware is identical. If a seller is asking full price for a locked device, negotiate down or look elsewhere. The unlock process is free from the carrier, but it takes time and requires the original account holder's cooperation, which is not always easy with a used purchase.

Common mistakes to avoid

Do not confuse a locked iPhone with a disabled iPhone. A disabled iPhone is one you cannot access because you entered the wrong passcode too many times. That is a security feature, not a carrier lock. The IMEI checker will not help with a disabled phone — you need to restore it through iTunes or iCloud instead.

Do not enter the IMEI into third-party websites that promise to unlock your phone or check status for a fee. These sites are often scams or sell your data. Stick to your carrier's official website.

Do not assume a phone is unlocked just because it works with your current SIM card. A locked phone works fine with its original carrier's SIM. The lock only matters when you try to use a different carrier's SIM. Always run the IMEI checker to be certain.

Do not type the IMEI incorrectly. It is 15 digits long and easy to misread. Copy and paste it from your phone's screen into the checker tool rather than typing it by hand.

Frequently Asked Questions

Can I check if an iPhone is unlocked without the IMEI?

Not reliably. The IMEI is the standard identifier carriers use to look up lock status. Some carriers will look up status by phone number if you have an account with them, but that only works if you are the account holder. The IMEI method works for any iPhone, whether or not you own the account.

What if I lost my iPhone and need to check its lock status?

If you have the original box or receipt, the IMEI is printed there. If not, contact your carrier with your account information and ask them to look up the IMEI and lock status for you. You will need to verify your identity as the account holder.

Does checking the IMEI unlock the phone?

No. The checker only tells you the current status. It does not change anything. To actually unlock a locked iPhone, you must contact your carrier and request an unlock separately. The carrier then processes the request and removes the lock remotely.

How long does it take for a carrier to unlock an iPhone after I request it?

Most carriers process unlock requests within 24 to 48 hours. Some complete it instantly. After the carrier confirms the unlock, you may need to restart your iPhone or insert a new SIM card for the change to take effect. If you do not see the unlock reflected after 48 hours, contact the carrier again.

Can I check the lock status of an iPhone that is not activated yet?

Yes. The IMEI checker does not require the phone to be activated or turned on. As long as you have the IMEI number, you can run it through the carrier's tool. This is useful when buying a new or refurbished iPhone before you set it up.