Like a prepaid calling card, all calls made on a block minute plan are rounded up to nearest minute. If you call a friend and listen to a 30-second answering machine message, you’ll be billed for one full minute. You’ll also be charged for one full minute if there’s a busy signal or no answer, although some block minute plans will only bill you if you let phone ring more than three times.

With a block minute plan, going over your allotted minutes can quickly get expensive. You’ll be charge a penalty rate for every additional minute you use. If you’re not careful, this can quickly add up to hundreds of dollars a month in unnecessary charges. The best defense is to buy more minutes than you think you’ll actually need and reduce your plan at a later date if necessary.

While it won’t endanger your life or harm your phone, cellular phone “cloning” will damage your bank account. A phone is cloned when someone steals its unique electronic serial number and telephone number. This allows thief to charge unauthorized calls to your account. If you think you have been a victim of cloning, contact your cellular phone carrier immediately.

Subscriber fraud is similar to cloning and occurs when a thief steals your personal information to sign up for a cellular phone account in your name. Once you’ve discovered that you’ve been victim of subscriber fraud, it can be difficult to prove to your cellular phone carrier that you did not incur charges.

Cellular phones are integral part of life for many individuals, but it’s important to be aware of potential problems that may arise from their use. Like any other modern electronic device, cellular phones are not without their drawbacks.