Consider a personal shredder to help you keep private information private. Don't give out your credit-card number to anyone who calls you on the phone. A criminal could call you claiming to be from a merchant you've just placed an order with and requesting updated credit-card information. Don't tell them anything. Instead, take down their number and verify it before returning the call.
Criminals often collect account numbers from telephone or Internet scams.
If one of your credit-card bills is late, call the card issuer right away. A criminal may have diverted your bill to a different address while continuing to rack up charges on your account. Check your statements carefully each month to make sure all charges are accurate. This is especially important for joint account holders, who may assume certain charges were made by their partner. Check your credit report at least once a year.