I want to get a frequent flyer credit card but I already have 3 credit cards with generous limits. I don’t need these credit cards and I want to cancel them and have this "possible credit" to go towards the new card. I heard once that canceling a credit card has a negitive effect on your credit score. Is this right? If so, how do I switch credit cards and avoid affecting my credit score in a terrible way?

Yes, it is right. Having active credit cards on your record is no problem. It shows that card issuers are willing to extend credit. If these cards have no balance on them, you should have no distress getting a new card. Apply and start using it.

If there are balances on your other cards, it is a different issue. You should pay them off, or transfer them to the card with the lowest interest rate and pay that off as quickly as possible. Then make sure you never have a balance on a card that exceeds about 30 percent of the credit limit.

Paying the monthly charges in full each month is the best policy. It also means not paying any interest.