By Doug Fletcher,Staff Writer

In terms of scams, it’s an old chestnut. Still, it’s worth a word to the wise, at least according to some e-mails making the rounds.

The scam goes like this: Someone calls, saying he or she is a technician for AT&T or another telephone company. The persons says he or she is checking lines, and asks you to dial 9, then 0, then to hit the pound sign, and hang up.

Don’t do it, say Peter Riley, a Verizon spokesman, and Phil Lindley, who handles media relations for the state’s Public Utilities Commission.

If the call happens to come into a home phone, even following the scammer’s instructions shouldn’t be a problem. But, typically, the call is made to a business that relies on PBX or Centrex switching technology, where it could create a problem.

The PBX and Centrex systems require users to dial 9 to get an outside line. By dialing 9, then 0, then hitting the pound sign, Riley and Lindley said, the caller could gain access to an outside line with a dial tone. From there, the world becomes their oyster.

Lindley said the scam “has been around for at least five years.”

Another telephone-based scam also has made the rounds in the past, and this one could result in bills on home systems as well as on business lines.

In it, a caller claims to have dialed a wrong number and says he or she has no change to make a second toll call. They ask that you dial star, then 7 and 2, then another phone number.

Don’t do that, either, says Lindley.

Dialing star-7-2 activates call forwarding, he said, sending calls to the phone number provided by the caller. From that point, collect calls could come in and be billed back to your home or business.

Riley said legitimate Verizon technicians would never call someone’s home or business and ask that they go through such steps. Nor would they ask for personal or business-related information.

“There are lots of scams out there,” he said, adding that people seeking personal information often are identity thieves. Once one has someone else’s credit card, Social Security or checking account numbers, it can be costly and ruin a person’s credit rating.

Riley said that besides the scams, people also need to be on the alert for so-called slamming operations.

In that case, a company illegally switches long-distance service, often resulting in higher charges as well as unwanted services.

Maine has successfully fought slamming and obtained penalties against companies that practiced it.