Having too many open credit cards is OK as long for the most part, depending on what your short/long term goal is.

As a rule of thumb:

- Make sure the balance on each card doesn't exceed 25% (some say 50%). If one card is near maxed out, it will hurt your Fico. BT it over.
- Check for Annual Fee (someone mentioned above)
- Analyze your cards to see which ones have a way low limit (e.g. $5k limit average, and one card with $500 limit). If the card with low limit can be raised up to $5k, then keep it, otherwise close it.

Your FICO score is mainly dependent upon credit balance, payment experience/history and inquiries. So having 15 cards with "positive" reporting each month will raise your credit score significantly. But if your credit score is 750 or above, it may or may not matter anyways.

However, note that some banks use their "internal" scoring system and not the FICO system. Banks will balk at high debt to income, but sometimes they may say something about the massive numbers of credit cards that go unused.

But if you've got your house, got your car, and the credit cards, then its really not a big deal either way.

For me, my fico hovers between 675-725 depending on my spending. Sometimes I run business expenses thru personal credit card to get points, and when the balance is reported to the credit reporting agency, my Fico will tank. But it comes back up once it is paid off. Mind you, my credit cards are paid in full each month.. but they may report the balance prior to paying in full.

Also, having many credit cards means many due dates and higher chance of late payment.

So the bottom line is, you have to manipulate your FICO depending on what you plan on doing. I know that under 700 will not get me the best rate for leases, so I tend to lay low on the cards if I know i am getting a new car.