Telephone customers in Utah should not give out their telephone credit card personal identification number - the last four numbers of telephone credit cards.

"There is a man who is calling under the guise of being a telephone company security agent in another city," said Carol A. Dunlap, US WEST communications public relations manager. "Several thousand dollars have already been billed to our customers' telephone credit cards," she said.In the past two weeks, the man has been targeting Salt Lake telephone customers with the prefix "942."

According to Dunlap, the caller uses several different tactics to get the numbers. One of his most common claims is that he needs their personal calling card number to cancel the credit card.

"He explains that someone is making overseas phone calls and claims that the only way for him to cancel the telephone credit card is by giving him the personal identification number," Dunlap said.