About a year ago, Therese Spencer noticed an unusual charge on her phone bill. Someone, known as a third-party biller, had inserted a $16 charge for an 800-number voice mailbox provider onto her phone bill.

Spencer called the company and found out that all a company needs is a person’s name, phone number, address and e-mail address to get phone companies to start billing people.

The company agreed to cancel its so-called service after Spencer complained, and after speaking with Verizon, which did the billing for the company, she got out of paying the charge altogether.

Then, on March 24, about a year later, Spencer noticed another bogus charge on her phone bill, again for a voice mailbox for an 800 number.

Spencer called the company, which insisted she had ordered the service. After all, it knew her name, address, phone number and e-mail address, representatives claimed.

The company even sent her a startup page from the Internet to show she had ordered the service, but their so-called safeguard, Spencer’s mother’s maiden name, was wrong.

Indeed, Spencer had been billed for services she hadn’t ordered. It’s called cramming, and it has been going on for years.

About five years ago, we wrote about a rash of cramming going on in Indiana. A Decatur restaurateur had discovered he was being charged $60 a month for four “services” he had never authorized, and every month the charges for the services got a little bigger

After her second experience with cramming, Spencer started investigating and found a Web site in which nearly 200 people had posted complaints about being crammed in just the last year.

And that’s just the people who realized they were being taken. Many people, especially small businesses, get crammed all the time and never know it because, like the Decatur businessman, they are too busy to carefully look at their bills.

The lesson to be learned is that people should review their phone bills each month. The Indiana Attorney General’s Office recommends people be on the lookout for charges for 800-number service, charges labeled “monthly fee” or for charges for services explained in general terms, such as voice mail, calling plan or membership.

People who discover what appear to be bogus charges should complain to the company that is billing them, but they shouldn’t stop there.

The Indiana attorney general used to handle cramming complaints, but jurisdiction has now been turned over to the Indiana Utility Regulatory Commission.

Anyone who believes he or she has been improperly billed should contact the consumer affairs division of the IURC, said Danielle McGrath, public information officer for the agency. That office’s number is 1-800-851-4268, and a report of cramming can be filed over the phone.

“That way we can track and log complaints,” McGrath said, and patterns of abuse become clear.

Meanwhile, the Office of the Utility Consumer Counselor recommends that victims contact the companies that crammed them, demand immediate removal of unwanted services, demand payments be refunded and demand a copy of any paperwork the company claims to have that shows the charges or services requested.

Harry Mitchell, a spokesman for Verizon, said that Verizon has what it calls first-call resolution. If a customer calls about what he considers a bogus charge, Verizon will automatically credit the account and offer the customer a cramming block, which means that no third-party billing will be permitted on phone bills.

Mitchell said that third-party billing is common, used by wireless-service companies, Direct TV and other companies, so it isn’t necessarily a bad thing.

“But there are some bad actors out there,” Mitchell said, and when Verizon discovers them through complaints, it terminates its dealings with them.

Reporting suspected cramming to the Utility Regulatory Commission also provides phone customers with a certain amount of protection.

Customers who refuse to pay disputed charges run the risk of having their phones disconnected, but if an investigation is ongoing, the phone company can’t disconnect a customer for refusing to pay disputed charges.