Accounts receivable days (DSO)

Days sales outstanding — how long you wait to get paid

Accounts receivable days, also called DSO (Days Sales Outstanding), measures the average number of days between making a sale and collecting the cash. It's the single most important operational metric for businesses that bill on credit terms, because high DSO directly translates into cash tied up in your balance sheet instead of your bank account.

What DSO actually measures

DSO is an average across all your receivables. A DSO of 50 on net-30 terms means customers are, on average, paying 20 days late. But averages can be misleading: if your top client pays in 10 days and three slow clients pay in 90, your blended DSO of 50 hides the concentration risk.

DSO is most useful when tracked as a trend over time. Rising DSO despite stable billing terms signals deteriorating collections — either customers are less creditworthy, or your invoicing and follow-up process has degraded. Falling DSO signals improving collections or a shift in customer mix toward faster-paying clients.

DSO benchmarks by industry

• Construction: 60–90 days. Retainage (typically 5–10% held until project completion), change order disputes, and slow general contractor payment cycles combine to create some of the worst DSO in any industry. GCs pay subs slowly because owners pay GCs slowly.
• Professional services (consulting, legal, accounting): 45–60 days. Monthly billing cycles plus client review time. The best firms invoice bi-weekly and maintain active collections, reaching 30–40 days.
• Manufacturing: 35–50 days. Depends heavily on end customer — industrial OEM customers pay slower than retail channel.
• Software / SaaS: Near zero for monthly card billing; negative for annual prepaid (you hold cash before delivering the service). The best SaaS companies push annual prepaid contracts hard precisely because of this cash flow advantage.
• Retail: 1–5 days for consumer retail (card transactions). 30–45 days for B2B retail (wholesale accounts with trade terms).

The cost of slow collections

The opportunity cost of high DSO is real and calculable. If your business has $1M in AR on DSO 90 vs DSO 45, the difference is $500k of cash that's sitting in your customers' bank accounts instead of yours. At a cost of capital of 8% (reasonable for a line of credit), that represents $40,000 per year in unnecessary financing cost.

More concretely: at $10M annual revenue, each day of DSO improvement frees $27,397 in cash (10,000,000 ÷ 365). Improving DSO by 15 days frees $411k — enough to avoid drawing $411k on a revolving line of credit.

Collections best practices

The companies with the lowest DSO share a few practices:

• Invoice same day or within 24 hours of work completion or milestone. End-of-month invoicing adds 15 days of DSO on average.
• Automated reminders at day 15 past due (friendly), day 30 (firm), day 45 (escalation), day 60 (personal call from account owner).
• Personal call at day 61+. The single most effective collections action. An email is easy to defer; a call is harder.
• Credit hold at day 90. No new work for accounts with 90-day overdue balances. This policy enforced consistently creates strong incentives to clear invoices before needing the next order.
• Deposit or milestone billing on large jobs: 25% deposit, 25% at 50% completion, 40% at completion, 10% at 30 days (replacing full retainage exposure).

Invoice factoring vs waiting

If cash flow is the constraint, invoice factoring lets you sell receivables to a factor at a discount (typically 1.5–3% of invoice face value) for immediate cash. Whether it's worth it depends on your cost of capital.

Example: $100k invoice due in 60 days, factoring rate 2.5%. You receive $97,500 now instead of $100,000 in 60 days. The $2,500 cost on a 60-day basis is approximately 15% annualized. If your line of credit costs 9–10%, waiting is cheaper. If you have no credit line and the alternative is passing up a growth opportunity that returns 20%+, factoring makes sense.