DSO is calculated as accounts receivable divided by revenue over a period, times the number of days in that period. A carrier with $80,000 in receivables and $480,000 of quarterly revenue has a DSO of about 15 days if it factors, or 35 to 45 if it bills brokers directly on standard terms.
Rising DSO means cash is arriving slower — either the broker mix shifted toward slower payers, invoices are going out late or incomplete, or disputes are holding up payment. It is an early warning that shows up before a cash crunch does.
The levers are invoice speed and accuracy (get a complete invoice with the POD out the day of delivery), broker selection (know who pays in 20 days and who takes 50), and using factoring or quick pay where the timing gap hurts.
Example
A carrier’s DSO drifts from 32 to 44 days over two quarters. Digging in, most of the increase traces to one large broker that quietly extended terms and to invoices going out three days late because PODs were arriving slowly. Fixing the POD workflow and re-negotiating the broker’s terms pulls DSO back toward 34.
Why it matters
DSO is the cash-flow vital sign. A profitable carrier can still fail if DSO climbs faster than it can fund fuel and payroll in the gap.