Abstract: 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.

Abstract: A line of credit optimized for a retailer and attached to a customer account at a financial institution is established for a customer of the retailer. A financial institution computer determines whether to advance funds through the line of credit for a transaction, then advances funds in one or more preselected loan increments to the customer account, up to a total available line of credit for the customer. The financial institution computer decrements the total available line of credit by the amount provided for the customer transaction and by a predetermined customer fee for each of the loan increments. The computer determines a value of a retailer fee to be paid by the retailer, involving a predetermined amount for each of the loan increments. The customer fee amount can be zero or discounted for customer transactions with the retailer. The retailer fee can be a rebate to the customer.