It only takes one stolen check from your mail box and some acetone to empty your entire bank account. A piece of cellophane tape covers the front and back of your signature, and then the check in place in a pan of acetone. This is a process known as “check washing” and it takes only about a half hour to rinse everything except the printer’s ink from the check. The things that remain on the check are your tape covered signature and the printer-inked information.

Buy a safe pen for yourself. One type of ink-the kind in gel pens manufactured by Uni-ball-resists acetone or other chemicals used in check washing. Instead of writing your full account number when told, list only some digits, such as the last four numbers of your credit card account. Firms commonly request that you note your entire account number, but there’s no need to comply.

To further protect your privacy, don’t put phone numbers on your checks. If you have to list one, make it your work number, not the number to your home. Another good idea is to get a Post Office Box number and use that instead of a street address as your mail-delivery point.

Definitely do not display on any check your Social Security or driver’s license number. To stop new checks from being stolen from your incoming mail, you need to specify that the delivery has to be sent not to your home but to your bank so that you can pick it up from there later.

Stealing your identity isn’t hard, but stealing your face is. Therefore, you should take advantage of an option given by certain credit card companies and retail stores that sponsor their own plastic: Your photo can be attached to your credit card.

If a company asks for your maiden name or your mother’s maiden name, tell them that you want to also use an alternative password to that one. Alternatively, you can fabricate an easy to remember bogus birthday or make up a maiden name.