How to Check IMEI, Activation Lock & Carrier Compatibility Before Buying a Used Phone
A used phone can look flawless and still be worthless. Three things decide whether it will actually work on your account: its IMEI status, whether it is still tied to someone else's activation lock, and whether it supports your carrier's network bands. Here is how to check all three.
1. Check the IMEI
The IMEI is a 15-digit serial number unique to every phone. Carriers use it to decide whether a device is allowed on their network. A phone reported lost, stolen, or left on an unpaid installment plan gets blacklisted — and a blacklisted phone will not activate on any major US carrier, no matter how good it looks.
How to find the IMEI
-
Any phone: dial
*#06#and it appears on screen. - iPhone: Settings → General → About.
- Samsung Galaxy: Settings → About phone → Status information.
- It is also printed on the original box and on the SIM tray of many models.
How to check it
Run the number through a free IMEI checker or, better, call the carrier you plan to use and ask them to verify it is clean. Ask two questions: is this IMEI blacklisted? and is there a financing balance attached? A phone can be clean today and blacklisted next month if the original owner stops paying — which is exactly why buying from a seller with a warranty matters.
2. Check for activation lock
Activation lock ties a phone to its previous owner's account. If it is still on, the phone is a brick — you cannot set it up, factory reset it, or use it, and there is no workaround. This is the single most common way people lose money on a marketplace purchase.
On an iPhone (Find My / iCloud lock)
Power the phone on. If it asks for an Apple Account email and password that is not yours during setup, walk away. A clean phone boots to the "Hello" setup screen with no sign-in demand. If you can get into Settings, check that Settings → [name] at the top is signed out and Find My iPhone is off.
On a Samsung Galaxy (FRP / Samsung account)
Same principle. After a factory reset, a clean Galaxy walks you through normal setup. A locked one demands the previous owner's Google or Samsung account credentials. Ask the seller to factory reset the phone in front of you and confirm it boots clean.
3. Check carrier compatibility
Two separate things get confused here:
| What it means | How to check |
|---|---|
| Unlocked — the phone is not restricted to one carrier | iPhone: Settings → General → About → Carrier Lock should read "No SIM restrictions." Galaxy: insert a SIM from another carrier and see if it connects. |
| Compatible — the phone supports your carrier's bands | Enter the IMEI on your carrier's "bring your own device" page. This is the definitive answer. |
An unlocked phone that does not support your carrier's bands will still give you poor service. This matters most with older models and with carriers that lean heavily on specific 5G bands. Our unlocked vs carrier-locked guide covers the distinction in more depth, and if you are moving to an eSIM-only device, read how eSIM activation works.
The five-minute checklist
- Dial
*#06#and write down the IMEI. - Verify the IMEI is clean with your carrier — no blacklist, no finance balance.
- Confirm the phone boots to a clean setup screen with no account sign-in demand.
- Check Carrier Lock reads "No SIM restrictions" (iPhone) or test a second SIM (Galaxy).
- Run the IMEI through your carrier's BYOD compatibility page.
If any step fails, the answer is no. There is no partial pass on a locked phone.
Or skip the checklist entirely
Every phone below ships IMEI-verified, activation-lock-free and carrier-unlocked, with a 1-year warranty behind it.
Frequently asked questions
Can a blacklisted IMEI ever be cleared?
Sometimes — if the original owner settles the balance or reports the phone found, the carrier can remove it. But that is entirely out of your control as a buyer, and it can take weeks or never happen. Treat a blacklisted IMEI as permanent.
What is the difference between activation lock and carrier lock?
Activation lock ties the phone to a person's account and makes it unusable. Carrier lock ties it to a network and just limits which SIM works. Activation lock is fatal; carrier lock is an inconvenience that can often be resolved with the original carrier.
Do I need the original box to check an IMEI?
No. Dialing *#06# on the phone itself gives you the real IMEI, and that is the one that matters. A box can be swapped; the phone cannot lie.
Are refurbished phones from Strictli already checked?
Yes. Every device is IMEI-verified, confirmed free of activation lock, wiped, tested and shipped unlocked. If anything is wrong in the first year, the warranty covers it. Compare our approach in what "certified refurbished" really means.
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