KANSAS CITY, Mo. -- Returning a phone call from an unknown area code could jack up your cell phone bill.
The Federal Communications Commission is warning people not to answer or return calls from nine area codes.
They call it the `one-ring cell phone scam`.
You get a call from an unknown number, with one of those area codes. It rings once, and then they hang up, hoping you'll call back.
You might not realize it, but the call is international, and as soon as you call back, your cell phone bill starts going up.
To protect yourself, don't answer if you don't know the number, and if they don't leave a message-- it's probably not important enough to call them back.
Experts say if you keep getting calls from the same number you can always block it.