Making only the minimum payment on time each month will certainly result in large interest bills and a debt which could take many years to repay, but it will not have a direct impact on your credit score because you are neither late in your payments nor in default (which you would be if you stopped making payments altogether). So as long as you meet the required payment amount and the due date, you won't be reported to the credit bureaux. But what may be reported is the fact that your credit utilisation is high (e.g. a balance of $8,000 on a card with a $10,000 credit limit), which may be the case if you are struggling to repay significant amounts of your balance. A high credit utilisation will have a negative impact on your credit score.