A prepaid card processor receives data for a line of credit for a prepaid card from a lending institution computer. The prepaid card processor makes available draws to the line of credit line on behalf of the lending institution computer in an authorization stream for a proposed purchase using the prepaid card as payment. When the line of credit is accessed, the processor loads the prepaid card with an additional value equal to one or more preselected loan increments so that the prepaid card then has a new amount totaling a previous amount plus the amount of value of the one or more preselected loan increments and so that the new amount exceeds or equals the value of a proposed purchase. Then the processor notifies the lending institution so that the line of credit balances on the lending institution computer and the prepaid card processor are kept in sync.