It’s happened to the best of us: you want to buy something using your credit card and find you don’t have enough available credit to complete your purchase. When you want to take advantage of low interest rates, high value credit card rewards, and the chance to pay off a purchase over time, it can be frustrating to be faced with a lower credit limit than you’d like.

So, what to do when this happens? One thing to try is simply picking up the phone and asking your credit card issuer to raise your credit limit. You might be pleasantly surprised to find that many card issuers will do this for their customers who are in good standing.

If, however, you find that your issuer won’t raise your credit limit, and you have a lower line of credit to use than you’d like, your best bet is to work on improving your credit score. Credit card issuers award lines of credit based on creditworthiness, and they also determine what your interest rate will be by looking at your credit report.

Scoring good credit

The best way to achieve a great credit score is to make sure all your accounts are in good standing. This means paying all your bills on time. Making reliable payments on your accounts counts toward 35% of your credit score. Another 30% of your score is calculated according to how much available credit you have, relative to how much you owe. Fifteen percent is dependent on the length of your credit history, and the remaining twenty percent is divided among the types of credit you have to your name and how much new credit you’ve applied for.

You can order a free copy of your credit report once a year, from each of the three major credit reporting bureaus: Experian, Equifax, and TransUnion. Many credit card issuers and banks also give customers fee access to their FICO credit scores at any time. Knowing your credit score is the first step toward figuring out why you’ve been offered a certain amount of credit, or turned down on a request for a higher line of credit.