The Division of Purchases and Supply has awarded a statewide contract for Collection. Services for Accounts Receivable.Our comprehensive accounting services offer a full range of billing and accounts receivable services designed for government contractors. Learn how to record retention receivable and payable, and why it can be essential for your construction business. In addition, before the contract is even signed, it is important to perform due diligence regarding the creditworthiness of your customers. An accounts receivable purchase agreement is a legally binding contract that governs the purchase of accounts receivable between parties in a specific location.