How to Check if Phone is Unlocked (iPhone & Android)
Three reliable methods to verify whether your phone is unlocked, plus what to do if it is still carrier-locked.
What Does "Unlocked" Mean?
A phone is unlocked when it can accept a SIM card from any carrier. A carrier-locked (or SIM-locked) phone only works with SIM cards from the carrier it was sold for. For example, an AT&T-locked iPhone only accepts AT&T SIM cards and rejects a T-Mobile or Verizon SIM.
Carriers lock phones sold on installment plans to guarantee the customer finishes paying. Once the phone is paid off and the carrier unlock requirements are met, the phone can be unlocked and used on any carrier.
Checking unlock status is critical when buying a used phone, because a locked phone may be useless if you are on a different carrier. For the underlying mechanism, see our SIM lock check guide. To identify the carrier a phone is locked to, see the IMEI carrier check guide.
Method 1: Check in iPhone Settings
On an iPhone, Apple added a direct unlock-status indicator in Settings:
- Open Settings > General > About
- Scroll down to Carrier Lock (or "Network Provider Lock" on iOS 16+)
- If it says "No SIM restrictions" β the iPhone is unlocked
- If it says "SIM locked" or shows a carrier name β the iPhone is locked
This is the fastest method and works on any iPhone running iOS 14 or later. For a full iPhone verification, see our iPhone check page.
Note: The Settings indicator only appears after the iPhone has been activated with a SIM at least once. A brand-new never-activated iPhone may not show the field.
Method 2: The SIM Swap Test
The most reliable physical test is to insert a SIM card from a different carrier and see if the phone accepts it. This works on iPhone and Android.
- Power off the phone
- Eject the current SIM and insert a SIM from a different carrier
- Power the phone back on
- Wait 30 seconds for it to search for a network
Interpret the result:
- Signal bars appear and you can make a call β the phone is unlocked
- "SIM Not Supported" / "Invalid SIM" / "Network Lock" message β the phone is carrier-locked
- "No Service" but no error β could be a band incompatibility, not a lock. Try a third SIM to confirm.
This test is definitive because it exercises the actual lock check that runs on the modem.
Method 3: IMEI Carrier Check (No SIM Required)
If you do not have a spare SIM from another carrier, use an IMEI carrier check service. Enter the 15-digit IMEI and the service returns:
- The carrier the phone is locked to (e.g., AT&T, T-Mobile, Verizon)
- Whether the phone is unlocked
- Unlock eligibility status
This is the best method when buying a used phone because you can run it before purchasing, using only the IMEI the seller provides. Pair it with a blacklist check and a warranty check for full coverage.
How to Check Unlock Status on Android
Android does not have a single universal Settings field like iPhone, but you can use the SIM swap test or an IMEI check. Some manufacturers add helpful indicators:
- Samsung: Settings > Connections > Mobile networks > Network operators. If you can manually select a network other than your carrier, the phone is likely unlocked.
- Google Pixel: Settings > Network & internet > SIMs. If you can add a second carrier and it connects, the phone is unlocked.
- General Android: Dial
*#06#and look for "Network Lock" status, or use the IMEI check method above.
Carrier Unlock Requirements (US)
If your phone is still locked, here are the unlock requirements for the major US carriers:
| Carrier | Requirements |
|---|---|
| AT&T | Phone paid off, 60 days active, account in good standing |
| T-Mobile | Phone paid off, 40 days active, account in good standing |
| Verizon | Auto-unlocks 60 days after purchase (policy since 2019) |
| Sprint | Phone paid off, 50 days active (now part of T-Mobile) |
Unlocking is free through the carrier once you meet the requirements. You can request it through your online account or by calling support. For the full iPhone unlock walkthrough, see our how to unlock iPhone guide.
Signs a Used Phone Is Locked
When buying used, watch for these red flags:
- The seller refuses to let you insert your own SIM
- The seller says "it works on any carrier" but cannot show you the Settings > Carrier Lock field
- The phone shows the original carrier boot logo or bloatware
- The IMEI check returns a specific carrier instead of "unlocked"
Always run the IMEI carrier check yourself before paying.
Frequently Asked Questions
Can an unlocked phone still use the original carrier?
Yes. An unlocked phone accepts any compatible SIM, including the original carrier SIM. Unlocking simply removes the restriction that forced the phone to one carrier. After unlocking you can keep using the same carrier or switch to any other. There is no downside to having an unlocked phone even if you do not plan to switch.
Can a phone bought on contract be unlocked?
Yes, once you meet the carrier unlock requirements. Most US carriers require the phone to be paid off, the account in good standing, and a minimum number of days active on the network (usually 40-60 days). Military personnel deployed overseas can request early unlocking. After meeting the requirements, you can request the unlock through your carrier account or by calling support.
How much does unlocking a phone cost?
Carrier-provided unlocking is free by law in the United States (FCC regulation) for eligible phones, and free in the EU and UK once the contract ends. Third-party unlock services charge between $15 and $80 depending on the carrier and model, but results are not guaranteed and some are scams. Always try the free carrier unlock first.
Will unlocking affect signal quality?
No. Unlocking only removes the SIM-lock restriction in software. It does not change the antenna, modem, or radio bands supported by the phone. Signal quality depends on the carrier network and the hardware bands, not on the lock status. An unlocked phone performs identically to the same phone when it was locked.
Conclusion
Checking whether a phone is unlocked takes seconds: check Settings > About on iPhone, or run the SIM swap test on any phone. If you do not have a spare SIM, use the IMEI carrier check with just the 15-digit IMEI. Always verify unlock status before buying a used phone, because unlocking a still-locked phone can take days and is not always possible if the original account is unpaid.