Debtors Days (DSO) refers to average number of days taken to collect receivables from customers, usually calculated as Trade Receivables divided by Sales multiplied by 365. Higher DSO may indicate collection delays. In MSME underwriting, it is read as part of the financial assessment and is usually compared across periods, peers, banking conduct and management explanations. For example, high debtor days may mean customers are paying slowly, while very high creditor days may show pressure on supplier payments. It matters because the number can influence eligibility, limit sizing, repayment comfort, leverage view and early-warning assessment. The common mistake is to use it mechanically; seasonality, accounting treatment, one-off items and data mismatches can change the credit interpretation.