Invoice requests should be created and submitted within two days of providing goods or services to an outside customer. An accounts receivable purchase agreement is a legally binding contract that governs the purchase of accounts receivable between parties in a specific location.This starts with drawing up a business agreement and establishing the terms and conditions of credit sales. Accounts Receivable (AR) represent money due for services performed or merchandise sold. The university sells goods and services to internal customers. Contract accounts receivable and payable (FI-CA) is a type of subledger accounting that is tailored towards the requirements of industry sectors.