What Is a Carrier Lock on an iPhone?
A carrier lock (also called SIM lock, SimLock, or network lock) is a restriction placed on an iPhone by the mobile carrier that originally sold the device. When an iPhone is carrier-locked, it can only be used with SIM cards from that specific carrier — inserting a SIM from any other network will show a "SIM Not Supported" or "SIM Not Valid" error.
Carriers lock iPhones to keep customers on their network, typically when the device is sold at a subsidized price or on an installment plan. Once the contract or payment plan is completed, most carriers will unlock the device upon request — but this is not automatic. Until then, the iPhone remains restricted to one network.
An unlocked iPhone (also called SIM-free or factory unlocked) works with any carrier worldwide. It accepts any SIM card from any network in any country — making it more valuable for resale and essential for international travel. Our free iPhone carrier check tells you instantly whether a device is locked or unlocked, and which carrier it's locked to.
How to Check If Your iPhone Is Unlocked
There are two reliable ways to check if an iPhone is carrier-locked or unlocked. If you have the device in hand, you can check in Settings. If you're buying remotely and don't have physical access, use our IMEI carrier check above — it's the only way to verify lock status without touching the device.
Choose your method:
Method 1: Check in Settings
Path: Settings → General → About → scroll to Carrier Lock.
If it says "No SIM restrictions" — the iPhone is unlocked. If it shows a carrier name — the iPhone is locked to that network.
Requires iOS 14 or later and physical access to the device.
Method 2: Check by IMEI (Remote)
Enter the iPhone's IMEI and serial number in the field above. Our tool queries carrier databases and returns the original carrier and lock status (Locked or Unlocked).
Best for buyers: Ask the seller for the IMEI before meeting and check remotely. No physical access needed.
To find the IMEI: dial *#06# or go to Settings → General → About. The serial number is in the same location. If you're buying online, ask the seller to provide both numbers before you commit.
Carrier Check Results: Locked vs Unlocked
When you run an iPhone carrier check, the result tells you two things: which carrier the device is associated with, and whether the SIM lock is active.
Unlocked (SIM-Free)
The iPhone accepts SIM cards from any carrier worldwide. No restrictions. This is the ideal status for resale, international travel, and carrier switching. An unlocked iPhone is typically worth more on the second-hand market.
Locked to [Carrier Name]
The iPhone is restricted to one carrier. Only SIM cards from that network will work. To use a different carrier, the device must be unlocked by the original carrier — this usually requires the account holder to request it. Do not buy a locked iPhone unless you use that same carrier or the seller unlocks it first.
Keep in mind that carrier lock and iCloud lock are two separate things. An iPhone can be carrier-unlocked but still have Find My iPhone enabled (iCloud locked), or it can be carrier-locked but iCloud-free. Always check both before buying — use our iCloud Check alongside this carrier check for a complete picture.
Free iPhone Carrier Check — All Apple Devices
Our free carrier checker works with every Apple device: all iPhone models (including iPhone 16, 15, 14, SE, and older), iPad models with cellular connectivity, and Apple Watch with cellular. Enter the IMEI and serial number to check the original carrier and lock status instantly.
For a complete device verification before buying a used iPhone, we recommend running multiple checks: iCloud Status Check (Activation Lock), IMEI Blacklist Check (stolen/lost), Apple Warranty Check, and this carrier check. Together, these four checks cover every major risk when purchasing a used Apple device.
For a single all-in-one report covering blacklist, carrier, iCloud, warranty, and device specifications, use our IMEI Check tool or see our premium services.
Carrier and lock status information is based on data available at the time of the check. The original carrier shown reflects where the device was first registered — the current carrier or SIM in use may differ. Lock status can change if the carrier processes an unlock request.
Frequently Asked Questions — iPhone Carrier Check
Carrier locked means the iPhone is restricted to one specific mobile network. It will only accept SIM cards from that carrier — inserting a SIM from any other network will result in a "SIM Not Supported" error. iPhones are typically locked when sold on installment plans or at subsidized prices. The lock can be removed by the carrier once the device is fully paid off, but this requires a formal unlock request.
Two ways: 1) In Settings: Go to Settings → General → About and look for "Carrier Lock." If it says "No SIM restrictions," the iPhone is unlocked. This requires iOS 14+ and physical access to the device. 2) By IMEI: Enter the IMEI and serial number in our checker above — the result shows the original carrier and whether the device is locked or unlocked. This works remotely, which makes it ideal for checking a device before buying it.
Yes, our basic iPhone carrier check is completely free and requires no registration. It shows the original carrier and SIM lock status (locked or unlocked). For more detailed carrier history or additional device information, see our
premium services.
Carrier lock restricts which SIM cards the device accepts — it's a network-level restriction set by the carrier.
iCloud lock (Activation Lock) ties the device to an Apple ID — it's an Apple-level security feature. These are completely independent: an iPhone can be carrier-unlocked but iCloud-locked, or carrier-locked but iCloud-free. When buying used, check both: use this tool for carrier status and our
iCloud Check for Activation Lock status.
Only the carrier that locked the iPhone can unlock it. You typically need to meet their requirements: the device must be fully paid off, the account in good standing, and any contract obligations completed. Contact the carrier directly to request an unlock — the process varies by carrier and country. Our tool checks the current lock status but does not unlock devices. Be cautious of third-party services claiming to unlock iPhones — many are scams.
Apple's carrier database uses both the IMEI and serial number together to look up device records. The IMEI identifies the device on carrier networks, while the serial number identifies it in Apple's internal systems. Providing both ensures an accurate match and prevents errors from mismatched or recycled identifiers. You can find both in Settings → General → About, or dial *#06# for the IMEI.
"SIM Not Supported" or "SIM Not Valid" means the iPhone is carrier-locked and the SIM card you inserted belongs to a different network. The device will not connect to cellular service until either: you insert a SIM from the correct carrier, or the carrier unlocks the device. Run a carrier check using the IMEI to find out which carrier the iPhone is locked to.
Only if you use the same carrier it's locked to — or if the seller agrees to unlock it before the sale. A carrier-locked iPhone is worth significantly less than an unlocked one because it restricts which networks you can use. If you travel internationally, a locked iPhone cannot use local SIM cards. Always check the carrier lock status before purchasing, and if the result shows "Locked," negotiate a lower price or ask for an unlock first.
Run these checks before buying any used iPhone: 1)
Carrier check — verify it's unlocked or compatible with your network (use this tool). 2)
iCloud check — verify Find My iPhone is OFF (use our
iCloud Check). 3)
Blacklist check — verify it's not reported stolen (use our
Blacklist Check). 4)
Warranty check — check remaining coverage (use our
Apple Warranty Check). 5) Ask the seller to sign out of iCloud in front of you. 6) Physically inspect the device. Only complete the purchase after all checks pass.
This specific carrier check is designed for Apple devices only (iPhone, iPad, Apple Watch). It requires both IMEI and serial number, which is how Apple's carrier database works. For carrier and lock status checks on Android devices (Samsung, Xiaomi, etc.), use our
universal IMEI Check tool which works with all brands.
They are the same thing — different names for the same restriction. "Carrier lock," "SIM lock," "SimLock," and "network lock" all refer to a restriction that limits which SIM cards an iPhone will accept. Apple uses the term "Carrier Lock" in iOS Settings, while many users and carriers use "SIM lock" or "SimLock." Our tool checks this status regardless of which term you use — the result shows whether the device is locked to a specific carrier or free to use with any SIM card.
