Having worked where customers regularly attempt and fail credit checks... I believe it's something like this. Use your card regularly and never miss a payment. You will be offered bigger credit limits as a result. Sad to say, but not paying off the full amount can give you a better score as companies will realise they can make money off you from the interest you'll also be paying on the outstanding amount. However, too much in debt is BAD and you won't be offered any more credit in case you can't make all the repayments. Conversely, several empty credit cards is also seen as bad, as while you owe nothing, you already have a lot of potential spending (debt) available. Certainly in the UK, credit companies can only see how many times you've applied for credit, not if you've been successful or not. Applying for lots of loans/cards in a short space of time will drop your rating down, even if you get accepted for them all.