Before you make another credit card application, first know how opening a new credit card is going to affect you. Opening a new credit card might boost your credit score if this is your first credit card. In other situations, opening a new credit card could hurt your credit score rather than help it.
A new credit card lowers your average credit age. Fifteen percent (15%) of your credit score is based on your credit age. There are two factors to your credit age. First, there’s the age of your oldest account and the average age of all your accounts. Opening a new credit card will lower the average age of all your accounts, especially if it’s been awhile since you last opened a credit account.
An inquiry is placed on your credit report when you open a new credit card even if you're not approved and even if you later decide not to accept the credit card. Inquiries are 10% of your credit score and an additional inquiry should cost a few credit score points. It may not sound like much but it could mean the difference between a good credit score and a bad one - a good loan rate and a less than ideal loan rate. (How Your Credit Score Affects Your Interest Rate)
Opening a new credit card could raise your credit utilization if you make a big charge on it the same day. If you charge a balance that takes up much of your credit limit, your credit score will take a hit. That’s because 35% of your credit score is based on how much of your available credit is being used. The more of your new credit limit you’re using, the more your credit score will hurt.
Watch out particularly, if you're opening up a store credit card, e.g. for a discount, and putting your purchase on the new account. Store credit cards are known for their low credit limits and a big purchase could spike your credit utilization instantly.
Opening a New Credit Card Isn't All Bad
In some cases, opening a new credit card can help improve your credit score. If you don't make any new purchases on your credit cards, including the new one, your overall credit utilization will drop and your credit score could increase.
You could get more points in the "types of credit" portion of your credit score, which is 10% of your score. Of course, this depends on the types of accounts you already have open and the type of credit card you open. Opening a new store credit card won't necessarily give you a boost in this area. But opening a new bank card can help, especially if you have only a few bank credit cards.
You should always open new credit cards on an as needed basis, rather than opening one simply to attempt to boost your credit score.