Every credit card user gets 18-50 days after she makes a purchase to pay the credit balance. This is known as the free credit period. During this period, the bank does not charge the card holder any interest. If dues are not paid on time, most card issuing companies charge 22-48% interest per annum. This is also shown as a monthly rate, which looks low but actually isn’t. Here’s a look at free credit period and what should one keep in mind about using this facility.