Financial Readiness
How a credit card charges you, how the grace period saves you, and why the minimum payment is a trap if you stop there.

Credit cards. Public domain image.
A credit card lets you borrow up to a limit and pay it back each month. Pay your full statement balance by the due date and you can skip interest on purchases, thanks to the grace period. The grace period is the time between your billing cycle ending and the due date, when you may owe no interest if you pay in full.
Pay only the minimum and interest keeps stacking up. The minimum payment is the least you must pay to stay current. It keeps your account in good standing, but it does not stop the interest. The one move that matters: pay the full statement balance, every month, on time.
The whole idea on one page. Pay in full and the grace period works for you. Pay only the minimum and interest works against you. Here is how to keep the grace period every month.
Pay in full: Pay your full statement balance by the due date and the grace period means no interest on purchases.
Pay only the minimum: The unpaid balance carries over and keeps accruing interest. A small purchase can cost much more.
Keep the grace period
Pay in full, every month, on time.
Source: CFPB
A card charges interest on any balance you do not pay off. The rate is your APR, which is the annual percentage rate, stated as a yearly rate. Many issuers calculate interest daily using a daily periodic rate, equal to the APR divided by 365, applied to your balance each day. That means it can compound daily. Pay your balance in full each month by the due date and you can avoid interest on purchases.
Card companies are not required to offer a grace period, but most do on purchases. If a card offers one, federal law requires your bill arrive at least 21 days before the due date. Grace periods usually cover purchases only, not cash advances or balance transfers, which can start charging interest right away. The rule is simple: pay your statement balance in full, every month, on time.
Paying only the minimum keeps your account current, but it does not stop interest. The unpaid balance carries over and keeps accruing interest, so a small purchase can cost much more over time. Pay more than the minimum when you can. When you do, the issuer generally applies the extra to your highest-APR balance first. There is no calculator on this page, so to gauge your own payoff, remember the rule: the more you pay each month, the faster you finish and the less interest you owe.
Here is why the rate, and the timing, hit harder when you are in uniform.
Military pay moves on a cycle, and a tight month can sneak up on you. Miss a payment and the cost of the card can climb fast, on top of fees you may not see coming.
60 days
Being more than 60 days late can let the issuer raise the APR on your existing balance.
Late and unpaid: A late fee hits, and once you pass 60 days the rate on what you already owe can go up.
Autopay on: Autopay for at least the minimum is a cheap backstop that keeps your rate where it is. Pay on time.
Fees to watch
Money tight this month? Call a free Military OneSource counselor before you miss a payment.
Source: CFPB
You do not have to figure this out alone. Every active-duty, Guard, and reserve member, and their family, can get free, confidential financial counseling. Call Military OneSource any time, or see your installation Personal Financial Manager or Personal Financial Counselor on base. The DoD Office of Financial Readiness (FINRED) has free tools and lessons, and the CFPB has plain-language guides and a way to file a complaint. All four are linked in Sources below.
If I pay in full, do I still owe interest on purchases?
No. On most cards, paying your statement balance in full by the due date avoids interest on purchases.
Do grace periods apply to cash advances?
Usually not. Cash advances often start accruing interest right away, with no grace period.
Does paying the minimum hurt my credit?
Not by itself. Paying at least the minimum on time keeps the account current. Missing payments can hurt your credit.