How long it takes, on average, to collect payment after you send an invoice. Every extra day costs you money.
Days sales outstanding (DSO) measures the average number of days between making a sale and collecting the cash. If your DSO is 45, it means on average you wait 45 days after invoicing before the money hits your bank account.
DSO is one of the most practical metrics for any business that invoices clients. It turns the abstract concept of “slow-paying customers” into a concrete number you can track and improve.
Revenue doesn't pay bills — cash does. A business billing $200K/month with a 60-day DSO has $400K permanently tied up in accounts receivable. That's $400K you can't use for payroll, growth, or emergencies. Cut DSO to 30 days and you free up $200K.
DSO also reveals collection problems before they become write-offs. If DSO is rising, it usually means either your clients are paying slower (a credit risk) or your invoicing and follow-up process has gotten sloppy. Either way, catching the trend early gives you time to fix it.
For service businesses — agencies, consultancies, contractors — DSO is often the single biggest lever for improving cash flow. The work is done, the value is delivered, but the cash is sitting in someone else's bank account.
Example: If your agency bills $200K/month and collects in 45 days on average, you always have about $300K in outstanding receivables. Getting clients to pay in 30 days instead cuts that to $200K — effectively putting $100K back in your pocket.
DSO = (Accounts Receivable / Total Credit Sales) x Number of Days
For a monthly calculation: (AR at month-end / credit sales for the month) x 30. For quarterly: use 90 days. The formula is flexible — just keep the time period consistent.
CentSight calculates DSO automatically from your invoicing and payment data. It tracks DSO over time, breaks it down by client, and flags accounts that are dragging your average up. You can ask “Which clients are paying the slowest?” and get a ranked list, so you know exactly where to focus your collection efforts. CentSight also shows how DSO changes affect your overall cash conversion cycle.
CentSight tracks DSO by client and alerts you to slow payers before they become collection problems.
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