Telecoms company AT&T has made coverage levels in West Virginia, Maryland and other US states available by ZIP Code.
Users are able to log on to the company's website and check 3G coverage in their area by typing in their ZIP Code.
Customers of the telecoms company will then be able to see coverage quality in their area right down to specific street addresses.
The company reminded customers of the service as it announced it was providing greater 3G coverage in western Maryland and West Virginia's eastern Panhandle.
J Michael Schweder, president of AT&T Mid-Atlantic, said: "Delivering dependable wireless coverage in more places for consumers who need to stay connected to work, family and friends is our ultimate objective.
"Our investments in western Maryland and the eastern Panhandle will help us ensure that our customers have access to the wireless services that help drive economic growth in traditionally rural areas."