DEAR HELOISE: Check the bank that issued your credit card to see if it offers a virtual account number. This VAN (as it is called) can be used for online purchases, where your security might be compromised. You can have as many as you like for various businesses or just go with one for all your online purchases. The bank recognizes VANs as belonging to your actual credit card, but if you are hacked, you need only close the one that was used. This avoids having to notify all those companies who regularly charge your card for services.