Before Buying a Used Cell Phone Check for Compatability Issues

Secondhand phones might not be unlockable

Published: November 2014

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Mobile phones aren't all that mobile when it comes to switching carriers—or even owners. It may seem like a no-brainer to accept a hand-me-down phone from a friend or family member or buy a used phone, but compatibility issues and carrier locks could stand in your way. A reader recently wrote to us about a phone she purchased from an AT&T customer that wouldn't unlock. The company was "holding it hostage," she said. "Do I have other options?"

That depends. You do have the legal right to unlock a mobile phone for use across carriers; it's something Consumers Union fights to maintain. Deep-rooted technology differences mean that some devices won't work on another carrier's network. There isn't much hope of using a Sprint phone or Verizon phone on AT&T or T-Mobile, for instance. You can probably use an AT&T phone to make calls on T-Mobile's network, but frequency-band differences might keep you from accessing its data network.

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The problem stems from who owned the phone first. Many AT&T and Sprint phones—and some Verizon phones—are locked to the account of their first owner. That means you can't take a pre-owned phone to another carrier and get service until the previous owner meets his or her obligations, that is, completes the term of the contract, for example, or makes sure the account is in "good standing" before parting company. Carriers also won't unlock a phone if it has been reported stolen.

Our reader was "burned" by unknowingly purchasing a phone from someone who hadn't met the terms of his contract. The AT&T rep we spoke with said that there's very little the carrier can—or will—promise if a phone's previous owner has unresolved matters; AT&T also said it would work with our reader to see whether there was anything it could do. If you have a similar problem, ask your carrier about its unlocking policy.

What does that mean for consumers?

First, don't accept a pre-owned phone until you call the carrier or at least check the carrier's website to be sure that the device is compatible with your desired network. (Many smaller carriers "piggyback" on larger networks. AT&T phones are compatible with Consumer Cellular, for example.) Buying a used phone? Make sure it's from a trusted source. (Amazon has a good reputation for resolving customers' problems with member merchants.)

Editor's Note:

This article also appeared in the January 2015 issue of Consumer Reports magazine.

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