The Facts Behind 12 Money Myths
Truth: We don’t recommend having too many open credit cards because it's tempting to use them all, and creates an administrative nightmare in terms of keeping up with the paperwork. All the same, your credit score will take a small hit when you cancel a card, and a much bigger hit if you cancel a bunch at the same time, including a negative effect on your credit utilization ratio (more on that here).
If you need to, we recommend canceling only one credit card per year. If you have more than that, vow not to use the rest, tuck them away in a drawer, and make a calendar reminder to cancel another one next year, and the year after that. And if you can, try and hold onto your oldest credit card--that long history is good for your credit score and report.