SIM Lock Check — See If a Phone Is SIM Locked, Free
Updated July 2026
A SIM-locked phone will only take SIM cards from one carrier — put in any other network’s SIM and you get “SIM not supported” instead of signal. Before you buy a used phone, switch carriers, or hand a phone down to a family member on a different network, a quick SIM lock check tells you whether the device will actually work. The check is free, takes under a minute, and only needs the phone’s 15-digit IMEI.
Check a phone right now with our free SIM lock check by IMEI — dial *#06# to see the IMEI, enter it, and read the SIM lock status, original carrier, and blacklist status in one free result. No sign-up.
What a SIM lock actually is
A SIM lock — carriers also call it a carrier lock or network lock; all three names mean the same thing — is a restriction the selling carrier places on a phone so it only activates with that network’s SIM cards. It exists because carriers subsidize phones on installment plans and want them to stay on their network until the device is paid off. The lock is enforced against the phone’s IMEI, the 15-digit serial number that identifies the hardware, which is why a SIM lock check works from the IMEI alone and why swapping SIMs or resetting the phone doesn’t change the status.
SIM lock vs SIM PIN — not the same thing
People searching “SIM lock” sometimes mean a different lock entirely: the SIM PIN. A SIM PIN protects the SIM card itself — if it’s enabled, the phone asks for a short code after every restart before the SIM will connect. Enter the wrong PIN three times and the card demands a PUK code, which your carrier prints on the original SIM packaging or shows in your online account; enter the wrong PUK ten times and the SIM card is permanently disabled and the carrier has to issue a replacement. That is a security feature on your card, controlled by you. A carrier SIM lock is a restriction on the phone, controlled by the carrier — this guide covers that one.
How to run a free SIM lock check by IMEI
- Get the IMEI: dial *#06# on the phone’s keypad and the 15-digit IMEI appears instantly. It’s also in Settings → General → About on iPhone, Settings → About phone on Android, and printed on the SIM tray or original box.
- Dual-SIM and eSIM phones show two IMEIs when you dial *#06# — both belong to the same device; use IMEI1, the primary.
- Enter the IMEI in our free SIM lock check — the result shows whether the phone is unlocked or still SIM locked to its original carrier, with no account or payment.
- Buying a used phone? Ask the seller for the IMEI before you meet and run the check first — a locked phone on the wrong network is the most common used-phone surprise.
Check the SIM lock status on the phone itself
iPhone has a built-in readout: open Settings → General → About and find the Carrier Lock row (labelled Network Provider Lock on some iOS versions). “No SIM Restrictions” means the iPhone is not SIM locked; if it names a carrier or says “SIM locked,” the lock is still on. This readout comes from Apple’s own activation servers, so it’s dependable.
Android phones mostly don’t show SIM lock status in settings. Phones sold by T-Mobile or Metro include a Device Unlock app that reports the lock status and can apply the unlock over the air once you qualify. On other Androids, the practical tests are the IMEI check above or simply trying a SIM from another network: “SIM not supported,” “SIM not valid,” “Network locked,” or a prompt for an unlock code all mean the phone is SIM locked. On eSIM-only phones (US iPhone 14 and later have no SIM tray), try adding an eSIM from another carrier or use the IMEI check.
What each SIM lock check result means
| Result | What it means | What to do |
|---|---|---|
| Unlocked / No SIM Restrictions | Any compatible carrier’s SIM or eSIM will activate. The phone can switch networks freely and is worth more when you sell it. | Nothing — you’re set. If buying, verify the blacklist status is clean too. |
| SIM locked to a carrier | Only that network’s SIMs will work until the carrier removes the lock. | The original carrier unlocks it free once its requirements are met — see below. |
| Unknown / no record | The databases the checker reads have no clear entry for that IMEI. This does not mean the phone is unlocked. | Re-check the digits, try a SIM from another network, or bring the phone to ProFix — we check devices free at the counter. |
How a SIM lock is removed
Only the carrier that placed the SIM lock can remove it, and carriers do it for free once their requirements are met — there is no legitimate paid shortcut. In broad strokes: the phone must be fully paid off and not reported lost or stolen, and some carriers also require a period of active service. Verizon automatically unlocks most phones 60 days after purchase; T-Mobile, AT&T, and prepaid brands like Metro and Boost unlock on request once the device qualifies. On modern phones the unlock is applied over the air — no code to type in on most iPhones. A factory reset never removes a SIM lock, because the lock lives against the IMEI, not in the phone’s software.
Want the full unlocking walkthrough? See Is my phone unlocked? — the SIM-swap test, carrier unlock requirements, and what to do if your phone is still locked.
Imported phone rejecting every US SIM even though it checks out unlocked? Run a country lock check — foreign carrier locks, Samsung region lock, and missing US bands are a different problem than a SIM lock.
A phone can be SIM-unlocked and still unusable — check the IMEI blacklist status too: a phone reported lost or stolen is blocked from US networks entirely, no matter its lock status.
Not sure which network the phone even belongs to? See the free IMEI carrier lookup guide — original carrier vs current SIM, and how prepaid brands map to the big networks.
Buying, selling, or stuck with a locked phone near North Providence, RI?
ProFix is a walk-in phone repair and buy/sell shop at 1712 Mineral Spring Ave in North Providence, RI — minutes from Providence and serving Pawtucket, Lincoln, Johnston, and Smithfield. We run a SIM lock and blacklist check on every device we buy and sell, we’ll check any phone free at the counter, and we can walk you through your carrier’s unlock process. An unlocked phone with a clean IMEI gets our strongest buyback offer.
Selling a phone? Get a same-day in-store offer — we verify the IMEI on the spot and pay the same day.
Shopping instead? Browse our tested, unlocked phones for sale — SIM lock and blacklist verified before they go on the shelf.
SIM lock check FAQ
How do I check a phone’s SIM lock status for free?
Dial *#06# to display the 15-digit IMEI, then enter it in the free SIM lock check on this site. The result shows whether the phone is unlocked or SIM locked to a carrier, plus its blacklist status — no account, sign-up, or payment.
How do I check the SIM lock on an iPhone without another SIM card?
Open Settings → General → About and look at the Carrier Lock row. “No SIM Restrictions” means the iPhone is not SIM locked. You can also dial *#06# and run the IMEI through the free checker on this site — no second SIM needed either way.
What does “SIM not supported” mean?
The phone is SIM locked to a different carrier than the SIM you inserted. Only the original carrier’s SIMs will work until that carrier removes the lock. Run a SIM lock check by IMEI to confirm which network the phone is locked to.
Is a SIM lock the same as a SIM PIN?
No. A SIM PIN is a security code you set that protects your SIM card — three wrong PIN entries require the PUK code from your carrier, and ten wrong PUK entries permanently disable the card. A SIM lock is a carrier restriction on the phone itself that limits which networks’ SIMs it accepts.
Does a factory reset remove a SIM lock?
No. The SIM lock is enforced against the phone’s IMEI, which identifies the hardware. Resetting the software, updating it, or changing the SIM card does not change the lock status — only the carrier that placed the lock can remove it.
How do I get a SIM lock removed?
Ask the carrier that sold the phone — unlocking is free once the device qualifies, which generally means it’s fully paid off and, on some carriers, has been active for a set period. Verizon automatically unlocks most phones 60 days after purchase. Avoid paid third-party “unlocking” services; only the carrier can legitimately remove its lock.
My phone shows two IMEI numbers — which one do I use for the SIM lock check?
Dual-SIM and eSIM phones display two IMEIs when you dial *#06#. Both identify the same physical device — enter IMEI1, the primary, in the checker.
ProFix — phone repair, buyback, and free IMEI checks in North Providence, RI. 1712 Mineral Spring Ave · (401) 999-0100. Walk-ins welcome.