Send all receivables over 61 days past due to OSDC. The period of time may be a month, quarter, or year.DSO formula: DSO = (Accounts receivable balance ÷ net credit sales) x days in period. Determine the days' sales in receivables for 20 V9 and 20Va. Assume 365 days in a year. Learn about the meaning of days sales in accounts receivable (AR). The purpose of this report is to review previous and current efforts to maximize the collection of debt owed to the State. Invoice payment terms should be kept to the minimum possible, generally no more than 30 days. Collection of receivables is most effective within the first thirty days of a billing. In order for the annual financial report to be accurate, the Controller's Office needs to record as accounts receivable any amounts not collected as of June 30.