It’s annoying when you’re busy — the phone rings, you drop what you’re doing to answer — only to hear a recording trying to sell you something.

If you haven’t given the caller your permission for the sales call, that’s an illegal robocall, according to the Federal Trade Commission.

Robocalls about charities or candidates are legal, but recorded sales messages that you haven’t given your written permission to receive are illegal, according to the FTC. Often, their pitch is a scam.

If you receive one of these calls, hang up and file a complaint with the FTC. And, sign up with the National Do Not Call Registry, a popular federal program for the public to reduce unwanted sales calls. To register your number go to www.donotcall.gov.

According to the AARP’s Fraud Watch Network, the FTC on a daily basis posts lists of numbers about which it has gotten complaints. Telecommunications carriers use the information to work on call blocking solutions; those solutions rely on phone numbers reported by consumers.

In June of this year, as a result of Do Not Call litigation brought by the U.S. Department of Justice, a federal court in Illinois ordered penalties against a Colorado-based satellite television provider.

The court found the company liable for millions of calls that violated the FTC’s rules and ordered the company to pay a $168 million judgment, the largest civil penalty for violating the FTC Act, according to the FTC.

The case shows “that companies will pay a hefty price for violating consumers’ privacy with unwanted calls,” said acting FTC Chairwoman Maureen K. Ohlhausen in a statement.

For more information about spotting and preventing scams, go to www.aarp.org/fraudwatchnetwork.