Question: How often do you have to use your credit cards to keep them active?
Answer: The answer to your question will vary depending on your creditor. Therefore the exact answer is probably written on your contract or available by contacting your creditor. Keep in mind, however, that in this economic crunch, creditors do not want to carry any more dead weight than they have to. These days "lean and mean" is the credit card companies' mantra--which is unfortunate for the consumer, because the card companies are far more ready to declare a card inactive than they would be in better economic times. As a general rule, I would say it's best to use your cards once very six months.
If you are worried that a closed account will negatively affect your credit score, you shouldn't. There are a few general guidelines to keep in mind regarding how your score is calculated. First of all, 60 percent of your credit score is based on on-time payment history and the amount of credit you carry. The length of your credit history affects another 15 percent. My point is that paying on-time is by far a more important factor in determining your credit score than having an account closed. Additionally, an account that gets closed through inactivity can be re-opened by simply calling the creditor.