Unlocked vs Carrier-Locked Phones

By SpringWangUpdated Research-based guide · How we choose

An unlocked phone works with any carrier’s SIM card or eSIM. A carrier-locked phone works only with the carrier that sold it until that carrier unlocks it. Which one is right depends on how long you will stay with your carrier and how much you value the freedom to switch.

The short answer

  • Buy unlocked if you might switch carriers, use a prepaid or low-cost carrier, travel abroad and want a local SIM, or plan to sell the phone later.
  • Buy from your carrier if you will stay for two or three years anyway and the carrier’s deal is clearly better than the unlocked price after you count the plan you have to take.

Unlocked does not mean compatible with everything

This is the most common surprise. An unlocked phone still needs:

  1. The right network bands. US carriers use different frequencies for 4G and 5G. A phone made for another region can be unlocked and still miss key US bands. Buy the US model.
  2. Calling features. Modern US networks carry voice calls over 4G and 5G (VoLTE and VoNR). A phone that does not support your carrier’s version may connect to data but fail at calls or Wi-Fi calling.
  3. Carrier approval. Verizon, in particular, checks each phone’s IMEI against its list of approved devices. For example, Nothing says its Phone (4a) Pro needs a manual registration through Verizon support before it will activate.

That is why our phone pages show carrier support only when the maker or carrier states it for that exact model, and show Unknown otherwise. We never guess from a band list.

How to check a phone before you buy

  1. Find the exact model number of the US version on the maker’s spec page or the store listing.
  2. Use your carrier’s bring-your-own-phone checker. Verizon explains its process in its bring your own device FAQ.
  3. If you already have the phone, check with its IMEI (dial *#06#).
  4. If you use a smaller carrier (Mint, Visible, Cricket and others), check with that carrier too. They run on the big three networks but keep their own device lists.

Getting a carrier phone unlocked

Carriers unlock phones once you meet their policy, which usually means the phone is paid off and has been active on the account for a minimum period. The details differ for prepaid and postpaid accounts and change over time, so check the current policy before you buy:

eSIM and dual SIM

Most phones in our catalog support eSIM, and the iPhone 16, iPhone 17 and iPhone 17e sold in the US accept eSIM only. The Moto G phones we list take a physical SIM and an eSIM at the same time, which is handy for a second line or travel. Each phone page shows whether eSIM support is confirmed.

Where to start

Every phone we recommend is sold unlocked in the US. Start with the best budget smartphones or use the phone finder to filter by carrier.

FAQ

Will an unlocked phone work on Verizon, AT&T and T-Mobile?
Not automatically. The phone must support the carrier's network bands and features such as VoLTE, and Verizon also has to accept the exact model on its network. Check the exact model with the carrier before buying.
Can I unlock a carrier phone later?
Usually, once you meet the carrier's unlock policy, which typically requires the phone to be paid off and active on the account for a minimum period. Each carrier sets its own rules and changes them from time to time.
Is a carrier phone cheaper?
Often at checkout, because the carrier discounts the phone in exchange for a plan or a monthly bill credit. If you leave early, you may owe the remaining balance and lose the credits.
What does "unlocked" mean in a store listing?
It should mean the phone accepts SIM cards or eSIM profiles from any carrier. A "carrier" or "prepaid" listing is usually locked. If a listing does not say, ask the seller before you buy.
Do unlocked phones get software updates?
Yes. Unlocked phones get updates directly from the manufacturer. Carrier versions also get updates, but each carrier approves them first, so timing can differ.
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