US mobile carriers began implementing a system this week to block the use of stolen mobile phones, part of an effort to curb rising thefts of smartphones such as the iPhone.
AT&T said Thursday it completed the second phase of its stolen phone database, which enables customers to report and block stolen wireless devices.
This means AT&T can share data about stolen phones with other GSM carriers to disable a stolen device.
CTIA-The Wireless Association, which represents the major US carrier, said the database for stolen phones was established as of a voluntary deadline Wednesday.
"CTIA and its member companies have always been advocates for wireless users' safety, which is why we're pleased our members met the voluntary deadline to create databases that will prevent stolen smartphones from being reactivated," association president Steve Largent said.
"While the GSM and CDMA databases are important, consumers also play a key role in protecting their information and preventing smartphone theft. By using passwords or PINs, as well as remote wiping capabilities, consumers can help to dry up the aftermarket for stolen devices."
The group encourages consumers to use a variety of apps on their smartphones to erase personal data or to track a phone if it is lost or stolen.
The database effort came after US authorities and cellphone carriers announced an effort in April to limit incentives to steal smartphones, which can be worth hundreds of dollars.
The major carriers and the Federal Communications Commission answered rising pressure from US police departments with a plan for a national database for stolen phones that would prevent their use by new owners.
In Washington, New York and other major cities, roughly 40 percent of all robberies now involve cellphones.
The London-based GSMA, a global association of more than 800 mobile operators, has also operated a counter-theft database based on phone serial numbers for years.
Explore further: AT&T to block stolen phone use this week