To check if an iPhone is unlocked, 1) go to Settings > Cellular > Cellular Data Options and look for labels like “Unlocked” or “No SIM restrictions,” 2) insert a different carrier’s active SIM card and see if the phone accepts it, 3) use the IMEI number on online tools like IMEI.info to check unlock status alongside other details, and 4) contact the original carrier directly with the IMEI for confirmation. The most reliable method is testing with a different SIM card, while combining multiple methods gives the clearest result since no single method is 100% accurate.

If you're buying a used iPhone or switching carriers, checking whether it's unlocked is important. An unlocked iPhone lets you use any carrier’s SIM card, which gives you more flexibility and better deals. Here’s how to tell if an iPhone is unlocked without guessing.

Check the Settings under Cellular

This is the quickest way if you have the iPhone in front of you. Go to Settings > Cellular (or Mobile Data, depending on region). Look for an option labeled Cellular Data Options or Mobile Data Options — inside that, there should be something called Voice Roaming, Data Roaming, or even a section like Carrier.

• If you see options like “Unlocked” or “No SIM restrictions,” then it's likely unlocked.
• If the only carrier listed is something like “AT&T” or “Verizon” and nothing about unlocking, it might still be locked.

Note: This method isn’t 100% foolproof because sometimes carrier settings can be outdated or cached.

Try Inserting a Different Carrier’s SIM Card

This is the most reliable real-world test.

Here’s what to do:

• Get a SIM card from a different carrier than the one the iPhone was originally used with.
• Turn off the phone, insert the new SIM, and power it back on.
• Wait a few moments.

What you’re looking for:

• If the phone accepts the SIM and shows service bars, you’re good — it’s unlocked.
• If you get a message like “SIM Not Supported” or “This SIM is Not Valid,” it’s probably locked to a specific carrier.

Make sure the SIM is active and working in another device first — otherwise, you won’t get an accurate result.

Use the IMEI Number to Verify Unlock Status

Every iPhone has a unique IMEI number. You can find it by going to Settings > General > About or by dialing *#06# on the Phone app.

Once you have the IMEI:

• Visit online IMEI checkers like IMEI.info or CheckMEND.
• Enter the IMEI and look at the report.

Some details these reports show:

• Whether the phone is reported stolen
• If it’s iCloud locked
• And sometimes, whether it’s unlocked from the original carrier

Keep in mind, though: many free tools don’t always show unlock status clearly. Some paid ones are more thorough, but they aren’t always 100% accurate either.

Ask the Original Carrier

If you know which carrier the phone was originally tied to, call their customer service or visit their website.

You’ll usually need:

• The iPhone’s IMEI
• Possibly the account info of the original owner

The carrier can tell you if the device is unlocked or not. This works best if the phone was unlocked through them officially — some carriers keep track of this long after the fact.

Basically, the easiest and most reliable method is inserting a different SIM. But if you don’t have access to one, checking Settings or using the IMEI can help. Just remember, no single method is perfect — combining a couple of these checks gives you the clearest picture.

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