Most people assume a phone locked to AT&T, Verizon or T-Mobile is worth a lot less than an unlocked one. On the marketplaces, it mostly isn't. At buyback companies, it can be worth a lot less. Which one applies to you depends on how you sell.
Quick answer
- Selling on Swappa or Back Market: a carrier-locked phone sells for about the same as an unlocked one, within a few percent either way.
- Trading it in: expect 10% to 20% less from the buyback companies that quote locked phones, and sometimes half as much.
What the data shows
Andover tracks prices for the same phone locked and unlocked across marketplaces and buyback companies every day. For each one, I compared the locked price to the unlocked price for the same model, storage and condition, then took the median across every model they price.
Source: Andover Analytics daily prices and buyback offers, fall 2026.
On Swappa, locked phones list at 100% to 103% of the unlocked price depending on the carrier. On Back Market, it's 101% to 104%. Basically no discount, and sometimes a tiny premium.
That surprised me at first, but it makes sense. On a marketplace, the buyer picks a phone for their own carrier. A Verizon customer shopping for a Verizon phone doesn't care that it's locked to Verizon. And since lots of people search by carrier, a locked listing can get in front of the exact buyer who wants it.
Buyback companies are a different story. Rick's iStock pays about 82% to 86% of its unlocked price for a locked phone. Gazelle barely discounts Verizon phones (99%) and takes about 12% off AT&T phones, but for T-Mobile phones it was paying only about 48% of its unlocked offer.
A buyback company has to resell your phone to someone, and it doesn't know who that will be yet. An unlocked phone works for anyone. A locked one only works for one carrier's customers, so they pay less for it.
What this means for you
If you're going to sell it yourself, don't stress about the lock. List it under the right carrier and you'll get about the same price as unlocked.
If you're going to trade it in, unlock it first if you can. On a $400 phone, the difference between 85% and 100% is $60. With Gazelle and a T-Mobile phone, it could be close to $200.
If you're shopping buybacks with a locked phone, compare carefully. The difference from one company to the next is much bigger for locked phones than unlocked ones.
How to get your phone unlocked
If your phone is paid off and your account is in good standing, your carrier will usually unlock it for free. Each carrier has its own rules about how long you have to have the phone and how to request it, so check their unlock page or call them. It usually takes a day or two.
Things that will stop an unlock:
- A balance on the phone. If you're still on a payment plan, you'll need to pay it off first.
- A phone reported lost or stolen. That's a blacklisted IMEI, and it can't be unlocked or sold on most platforms.
- A brand new line. Some carriers require the phone to be active on their network for a while before they'll unlock it.
Watch out for financed phones
A phone with a balance still on it is a different problem from a carrier lock. If the original owner stops paying, the carrier can blacklist the phone, and then it won't work on any network. Swappa requires a clean IMEI to list, and most buyback companies check too.
If you're buying a used phone, run the IMEI through a free checker before you pay. If you're selling, make sure it's paid off so your buyer doesn't get a nasty surprise.
Common questions
Is an unlocked phone worth more than a locked one?
On marketplaces like Swappa and Back Market, not really. Locked phones sell for about the same as unlocked ones there. At the buyback companies we track that quote locked phones, unlocked ones are typically worth 10% to 20% more, and sometimes double.
Does unlocking a phone increase its value?
It does if you're trading it in. It barely matters if you're selling on a marketplace. Since unlocking is usually free once the phone is paid off, it's worth doing either way.
Can I sell a phone that still has a balance on it?
You usually can't sell it cleanly. Swappa won't list it, and buyback companies may reject it or pay much less. Pay off the balance first.
Which carrier-locked phones get the biggest discount?
In our data, T-Mobile locked phones got hit the hardest at buyback companies. Gazelle was offering about half its unlocked price for them.
If you want to see the trade-in math across every buyer, read Trade-in vs selling yourself. For current prices on your exact phone, locked or unlocked, check our price pages.