What "unlocked" means and why it matters

An unlocked phone is one that will work with any wireless carrier — Verizon, AT&T, T-Mobile, or a smaller provider like Mint Mobile or Visible. A locked phone only works with the carrier that sold it to you. If you have a locked phone and want to switch carriers, you have to contact your current carrier and ask them to unlock it first.

The reason this matters: locked phones are cheaper upfront because the carrier subsidizes the cost. But you lose the freedom to switch without waiting for an unlock, and you cannot use the phone internationally on a local SIM card without that unlock. If you buy a used phone, knowing whether it is locked tells you whether you can actually use it with your chosen carrier.

Key Takeaways

  • You can check if your phone is locked by trying to insert a SIM card from a different carrier, or by calling your current carrier and asking directly.
  • On iPhone, go to Settings > General > About and look for a "Carrier Lock" field; if it says "No SIM restrictions," your phone is unlocked.
  • On Android, the method varies by manufacturer, but Settings > About Phone usually shows carrier lock status, or you can call your carrier to confirm.
  • If your phone is locked and you want to unlock it, contact your carrier's customer service — most carriers unlock phones for free once your contract is complete or paid off.
  • A locked phone works perfectly fine on its own carrier; the lock only prevents you from switching to a different one.

The fastest way: call your carrier and ask

The simplest method is to contact your wireless carrier directly. Call the customer service number on your bill or on the carrier's website, and ask whether your phone is locked. They can tell you in under a minute and do not need any special information from you — just your phone number or account details.

This is also the most reliable way, because the carrier's system is the source of truth. A representative can also tell you whether your phone is may be able to access for unlocking if it is currently locked, and what the timeline is.

Checking on iPhone

On an iPhone, open Settings, then tap General, then About. Scroll down and look for a field called "Carrier Lock." If it says "No SIM restrictions," your phone is unlocked. If it shows your carrier's name (like "Verizon" or "AT&T"), your phone is locked to that carrier.

This method works on iPhone 12 and newer. On older iPhones, the Carrier Lock field may not appear in Settings, which usually means the phone is unlocked — but calling your carrier is still the safest way to confirm.

Checking on Android

Android phones vary by manufacturer, so the steps are not identical across all devices. On most Android phones, go to Settings, then About Phone, and look for a field related to SIM lock or network lock. Samsung phones sometimes show this under Settings > About Phone > SIM Card Status. Google Pixel phones may show it under Settings > About Phone > SIM Status.

If you cannot find the information in Settings, your carrier can tell you over the phone. You can also insert a SIM card from a different carrier (if you have one available) and see whether the phone recognizes it — if it does, the phone is unlocked.

Testing with a different SIM card

If you have access to a SIM card from a different carrier, you can insert it into your phone and see what happens. Power off your phone, remove the current SIM card, insert the new one, and power back on. If the phone connects to the new carrier's network, your phone is unlocked. If you see an error message or the phone does not recognize the SIM, your phone is locked.

This test is practical if you have a friend with a different carrier or if you are considering switching and want to test the new carrier's network first. Keep in mind that some carriers require you to set up a SIM card before it will work, so a blank SIM from a different carrier may not work even if your phone is unlocked.

What to do if your phone is locked

If your phone is locked and you want to unlock it, contact your carrier's customer service. Most carriers unlock phones for free once your contract is complete, your device is paid off, or you have been a customer for a certain period (often 40 to 60 days). Some carriers unlock phones when ready if you are in good standing.

The carrier will verify your account, confirm that you meet their unlock requirements, and then send an unlock code or process the unlock remotely. On iPhone, you may see a prompt to enter an unlock code; on Android, the process is usually automatic. After the unlock is processed, your phone will work with any carrier's SIM card.

Unlocking a used phone you bought secondhand

If you bought a used phone and it is locked to a carrier you do not use, you have a few options. The best one is to contact the original carrier and ask them to unlock it. You will need to provide the phone's IMEI number (dial *#06# on most phones to see it, or find it in Settings > About Phone). The carrier may ask for proof that you own the phone, or they may unlock it without verification depending on their policy.

If the original owner is still on the account, the carrier may require their permission to unlock. If you cannot reach the original owner or the carrier refuses, you can also contact the phone manufacturer — Apple and Samsung both have processes to unlock phones in certain situations, though these are slower and have stricter requirements.

Frequently Asked Questions

Does an unlocked phone cost more money per month?

No. An unlocked phone and a locked phone cost the same per month on any given carrier's plan. The difference is that you bought the unlocked phone at full price upfront, while a locked phone was subsidized by the carrier when you signed a contract. Once you own either phone, the monthly bill is the same.

Can I use an unlocked phone internationally?

Yes. An unlocked phone lets you insert a local SIM card from a carrier in another country, which is usually much cheaper than paying your home carrier's international rates. A locked phone cannot use a foreign SIM card, so you would have to pay your home carrier's roaming fees or go without service.

Will unlocking my phone void the warranty?

No. Unlocking a phone through your carrier does not void the manufacturer's warranty. The phone still has the same coverage it had before. If you use a third-party unlocking service, that may affect your warranty, but carrier unlocks are safe.

How long does it take to unlock a phone?

Carrier unlocks usually happen within minutes to a few hours. Some carriers process them when ready over the phone; others send an unlock code by email or text. If the carrier processes it remotely, you may need to restart your phone for the unlock to take effect.

What is an IMEI number and why do I need it?

An IMEI is a unique 15-digit identifier for your phone. Carriers use it to look up your device in their system. You can find it by dialing *#06# on most phones, or in Settings > About Phone. You only need it if you are trying to unlock a phone you do not have an active account with.