A high DSO number can indicate that the cash flow of the business is not ideal. It varies by business, but a number below 45 is considered good. It's best to track the number over time. If the number is climbing, there may be something wrong in the collections department, or the company may be selling to customers with less than optimal credit. In any case, the company's cash flow is at risk. The debt collections experts at Atradius suggest that tracking DSO over time also creates an incentive for the payments department to stay on top of unpaid invoices. Needless to say, a small business can use its days sales outstanding number to identify and flag customers that are weighing it down by not paying promptly.