Revealing your calling-card-number
Your calling-card-number is like money in the bank to scam artists who can use it to sell long-distance calls to locations around the world. Here are some potential scams that may con you out of your calling-card-number:

Someone calls you at home posing as a telephone representative and asks for your calling-card-number to check on unauthorized charges billed to your account. Or, the caller may tell you that your calling-card-number has been deactivated in error and that he needs you to "verify" your number so it can be re-instated in the system.

Cramming and Slamming
According to the National Fraud Information Center, Cramming is currently the top scam for 1998. "Cramming" occurs when telephone customers are charged for services they’ve never ordered or received. Close behind came "Slamming," which occurs when customers have their telephone service switched without their permission. Here are some common ways you could be crammed or slammed!

You may receive a sweepstakes promotion in the mail telling you to call an 800 number to win a prize. When the call is made, an automated system is activated and you are unknowingly enrolled in a club or program, and the charge is placed on your phone bill. Or, you may fill out a contest entry form, only to discover later than the promoter changed your long-distance service without your knowledge or have used your phone number to sign you up for a calling card, voice mail or some other service. In many instances, the fine print on the form said that by entering the contest, you have signed up for the service.

You may receive a call from a telemarketer asking you to switch your long-distance service. Although you say you are not interested in switching, your long-distance service is changed anyway.  

Placing International Calls Without Realizing It
It’s not always easy to tell if you’re dialing an international telephone number. In most cases, you have to dial "011’ to begin a call to a foreign country. But there are locations outside the U.S. whose telephone numbers may look like domestic long-distance calls, but they are actually international calls and international rates apply. For example, 809, 284 and 876 are area codes in the Caribbean.

There are many scams that deceive consumers into calling international numbers. You may see an ad for a service that directs you to call a specific number, or you may receive a page, an e-mail message or an ‘urgent" message on your answering machine. All messages direct you to call a number for more information – almost always an international number.

Call Forwarding Scam
You may receive an automated message on your telephone that says you have won a prize or money. The message directs you to dial a 2-digit code preceded or followed by the * or # key (such as *79 or 72#), and then an 800 number to claim your prize. When you dial the number, you are not connected to anyone. What this procedure has done, though, is program your telephone to forward your calls to a long distance operator. Con artists can then call your number, be forwarded to the long-distance operator and place calls that are billed to your home telephone number.