Abstract: Generally speaking, the invention provides for credit score maximization, by streamlining a user's credit and debit decisions in accordance with preselected parameters. A user can be a person or a business, and parameters can be manipulated by interface with a mobile or desktop application, online portal, or other such mechanism. When a transaction occurs at a merchant POS, the amount is processed by an algorithm that determines how that payment can be distributed between the user's available accounts to meet that user's desired account portfolio. Methods are provided for use of a temporary credit facility and a related payment device that will yield seamless integration, and in the spirit of credit rating exploitation, prevent overdraft or debt default fees, and negative credit marks with the major credit bureaus.