Will this phone work for me?

Four checks tell you whether a used phone will work for you: is it unlocked, does your carrier's network support it, is its IMEI clean, and is it free of account locks. Each carrier, checker and model-code fact below links to the page it came from, with the day we read it.

Carriers change their networks and rules. Before you pay, confirm with your own carrier's checker, and message the seller if the listing leaves anything out.

1. Is it unlocked?

Metro by T-Mobile explains: "Unlocked" means your phone isn't "locked" to a specific carrier or network and can work with multiple service providers. Metro by T-Mobile, read Oct 9, 2026.

If you bought your phone through a carrier, there's a good chance it is locked. Metro by T-Mobile, read Oct 9, 2026.

It lists where to look in Settings: Apple: Settings → General → About → Carrier Lock Samsung: Settings → Connections → More Connections Settings → Network Unlock Metro by T-Mobile, read Oct 9, 2026.

Each carrier has different policies for unlocking phones. Metro by T-Mobile, read Oct 9, 2026.

If a listing does not say whether the phone is unlocked, treat it as unknown and message the seller before you buy.

2. Which network does your carrier use?

A prepaid carrier's phones need to work on the network it uses. These are the carriers whose own site states their network.

Cricket also warns: NOT ALL 5G DEVICES FROM OTHER CARRIERS WILL HAVE ACCESS TO 5G SERVICE ON THE CRICKET NETWORK. Cricket Wireless, read Oct 9, 2026.

A phone made for another country is the usual reason to look closer. For Samsung phones, see Galaxy international vs US models below.

3. Check the IMEI

The IMEI is a number that identifies one phone. The checkers below ask for it, so get it from the seller before you buy.

Metro by T-Mobile says: You can find your phone’s IMEI by dialing *#06# or by going into its settings. Metro by T-Mobile, read Oct 9, 2026.

You can find the serial number, EID, IMEI/MEID, CDN, and ICCID in several places, including in Settings, on the device itself, in the Finder, or on the original packaging. Apple Support, read Oct 9, 2026.

Your carrier's compatibility checker

• Metro by T-Mobile: bring your own phone: Device compatibility verified during activation. (read Oct 9, 2026)
• Cricket: device compatibility (IMEI): Switching to Cricket starts with an unlocked device. You can check compatibility with your phone’s IMEI (Device ID). (read Oct 9, 2026)
• Visible: bring your own phone
• Straight Talk: compatibility checker: Find out if your phone works on our network with the compatibility checker (read Oct 9, 2026)
• T-Mobile: IMEI compatibility check: Look up your IMEI to see if your phone is compatible with the T‑Mobile network using our checker tool below. (read Oct 9, 2026)

We link only to checkers that the carrier or the industry publishes itself. We run no IMEI lookup of our own.

Is it reported lost or stolen?

CTIA's Stolen Phone Checker lets consumers and commercial users know if a mobile device is reported lost or stolen before they make a purchase. CTIA Stolen Phone Checker, read Oct 9, 2026.

4. Account locks

Don't take ownership of any used iPhone or iPad if it's protected by Activation Lock. Apple Support, read Oct 9, 2026.

A device is ready for you to use when you see the Hello screen. Apple Support, read Oct 9, 2026.

if your protected device got stolen and erased, only someone with your Google Account or screen lock could use it. Android Help, read Oct 9, 2026.

More on carrier, screen and account locks: phone unlocking and security guide.

5. eSIM

An eSIM is a digital version of a physical SIM card that is embedded in your device. Metro by T-Mobile, read Oct 9, 2026.

To use an eSIM with Cricket, your device is unlocked and eSIM-capable. Cricket Wireless, read Oct 9, 2026.

To use two carriers, your carrier must unlock your iPhone, or both plans must be from the same carrier. Apple Support, read Oct 9, 2026.

Apple's US models of these iPhones use eSIM only, with no SIM card tray (from Apple's tech specs):

• iPhone 14 (Apple tech specs)
• iPhone 14 Plus (Apple tech specs)
• iPhone 14 Pro (Apple tech specs)
• iPhone 14 Pro Max (Apple tech specs)
• iPhone 15 (Apple tech specs)
• iPhone 15 Pro (Apple tech specs)
• iPhone 15 Pro Max (Apple tech specs)
• iPhone 16 (Apple tech specs)
• iPhone 16 Pro (Apple tech specs)
• iPhone 16 Pro Max (Apple tech specs)
• iPhone 17 (Apple tech specs)
• iPhone 17 Pro Max (Apple tech specs)

Galaxy international vs US models

Samsung's US store lists its Galaxy phones under model codes that carry a U after the model number, for example SM-S938U and SM-A576U. Sources: Samsung US, read Oct 9, 2026, Samsung US, read Oct 9, 2026.

Samsung sells the same Galaxy phone under different codes in different countries. We have checked these codes against Samsung's own store pages:

• SM-S928B: Samsung's UK store lists the Galaxy S24 Ultra under this code. Samsung UK, read Oct 9, 2026
• SM-A165F: Samsung's Levant store lists the Galaxy A16 under this code. Samsung Levant, read Oct 9, 2026

On a Galaxy listing whose model code is one of these, the buy box repeats the line above for that code. A listing with no model code, or a code not listed here, gets no extra line.

This page does not list network bands for each model, because we could not read a band list from Samsung or a carrier. For a phone sold under a non-US code, check the listing's code (on the phone: Settings, About phone), then use your carrier's IMEI checker above. Only your carrier's own check settles whether a given phone works for you.

Related

• Used phone prices by condition
• Returns policy
• Samsung Galaxy A53 model-number checklist