*Because a credit card is an open line of credit, they require disciplined use. If a customer is assigned a credit line with a minimum payment higher than they can afford, they must take care not to charge too much on the card. | *Because a credit card is an open line of credit, they require disciplined use. If a customer is assigned a credit line with a minimum payment higher than they can afford, they must take care not to charge too much on the card. |