An accounts-receivable management system in which customers mail payments to a post office box affiliated with the companyÂ’s bank. Bank employees check the box frequently, deposit checks into the companyÂ’s checking account, and then either electronically transmit or telephone the check details to the companyÂ’s accounts receivable department. The process gives the company access to its money more quickly and saves the company from hiring more staff to process the checks. The bank charges a fee for the lockbox service.