A consumer is prequalified for a line of credit attached to a checking account by a lending institution computer responsive to consumer underwriting data. The lending institution computer makes available draws to the line of credit line in an authorization stream for a proposed payment from the checking account. When the line of credit is accessed, the checking account is credited with an additional value equal to one or more preselected loan increments so that the account 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 payment. Next, a new value for the line of credit balance available is determined, accounting for value credited to the checking account and a preselected loan advance fee for each loan increment credited to the account.