As more and more people fall behind on paying their bills—due to job loss or other problems—bill collectors (a/k/a debt collectors) are busier than ever.

If any of them are calling you, here’s some advice from Sally Herigstad, C.P.A., from her book, Help! I Can’t Pay My Bills...

“When debt collectors call, never forget that you have the ultimate weapon of defense: hanging up. You don’t have to talk to them, even if they tell you that you do. The only thing you really want out of these callers is a chance to tell them never to call again, and to send you something in writing. You want them to mail you something so you can get their name and address.”

If you cringe every time your phone rings, and you wonder whether or not you should answer it, you need to have Caller ID, with a display unit on at least one phone or, better yet, several. And if the display says UNAVAILABLE or some number you don’t recognize, chances are it’s a bill collector (if you’re behind on payments), somebody soliciting money for a possibly phony organization you never heard of, or a telemarketer trying to sell you something, even if you’re on a Do Not Call list.

More advice from the book, with our comments in parentheses: “Never tell debt collectors where you work” (say that you’re self-employed), “how much you make” (ask them the same question), “what bank you use, or any of your relatives’ names. Never tell them your checking account number, your credit card information, your Social Security number, or your mother’s maiden name.” (And don’t let them pressure you into promising something you can’t deliver on.)