Pay attention to #4 if you are married

When it comes to the number of credit cards in your wallet, there is a sweet spot that will provide you with the best FICO score.
After all, if you have too many credit cards, the credit-scoring bureaus worry that you might get yourself into a financial bind. If you have too few, they do not have enough information about your spending behavior.
So the credit-scoring bureaus give the best FICO scores to people who have three to five credit cards.
If you have fewer than three credit cards, or if you have more than five credit cards, here are some things to keep in mind:
1. If you need to open credit cards, make sure that you open credit cards that report to all three credit bureaus (Equifax, TransUnion, and Experian). Otherwise, your efforts will be for naught.
Here is a list of the best credit card offers out there that report to all three bureaus.
2. If you need to apply for more than one credit card to reach the three-to-five goal, apply for them all at once. Part of your credit score is based on the age of your accounts. If you open one now, and then wait six months to open another, you will lower the average age of your accounts.
3. If you have more than five credit cards, do not close them. Doing so could hurt your score by lowering the average age of your accounts. Instead, simply stop using the extra cards and allow them to become inactive.
4. Never apply for credit jointly with your spouse. You and your spouse should each apply for three to five cards so that you both build separate credit identities.
This is important in case you ever find yourself in a financial bind and unable to pay all of your bills. If you have joint credit cards, both of your credit scores will take a hit, but if you build separate credit profiles, only one spouse’s credit score will suffer. The other can be preserved and then leveraged for loans.
P.S. Remember: Make sure you apply for credit cards that report to all three of the credit bureaus. Here are some of our favorite credit card offers.