Days Sales Outstanding (DSO): Calculate It, Then Cut It
The short answer: Days Sales Outstanding (DSO) is the average number of days it takes you to get paid after you invoice a job. The formula is DSO = (accounts receivable ÷ revenue over a period) × days in that period. A lower number means cash comes back faster; a higher number means your money is sitting in other people's bank accounts. For most field-service and contracting businesses a DSO under 30 days is healthy, 30–45 is workable, and past 45 you are effectively financing your customers. You cut it by invoicing the day the work is done, making payment effortless, and chasing overdue balances on a schedule instead of when you happen to notice. CRMb invoices straight off the finished job, sends a public payment link the customer can open and sign in seconds, and shows every unpaid balance in Reports so nothing ages quietly.
You can have a full schedule, strong margins, and still run out of cash — because profit on paper is not money in the bank until the customer actually pays. DSO is the number that measures the gap. Here is how to calculate it, what to aim for, and the specific moves that pull it down.
What DSO actually measures
Revenue tells you what you earned. DSO tells you how long that earning stays stuck as an IOU before it becomes cash you can spend.
Think of it as the average lag between "job done, invoice sent" and "money received." If your DSO is 40, then on average every dollar you bill takes 40 days to land in your account. During those 40 days you are still paying your crew, your suppliers, and your overhead out of pocket. The higher the number, the more of your own cash you have tied up funding work you already finished.
That is why two businesses with identical revenue can feel completely different. The one collecting in 20 days always has cash to make payroll and buy materials. The one collecting in 50 days is constantly waiting on checks, dipping into a line of credit, and feeling broke despite being busy.
The formula, kept short
Two lines cover it. Pick a period — a month, a quarter, a year — and stay consistent.
Days Sales Outstanding:
DSO = (accounts receivable ÷ revenue in the period) × number of days in the period
Accounts receivable is the total of all invoices that are billed but not yet paid, measured at the end of the period. Revenue in the period is what you billed over that same stretch.
A quick example. Over a 30-day month you billed $60,000, and at month end $40,000 of invoices are still unpaid:
DSO = ($40,000 ÷ $60,000) × 30 = 20 days
On average you are getting paid 20 days after you invoice. Run the same calculation every month and watch the trend — a DSO that creeps upward is an early warning that collections are slipping, usually well before it shows up as a cash crunch.
What counts as a good DSO
There is no universal target, but there are useful ranges for service businesses that invoice after the work.
- Under 30 days — healthy. Your billing and collections are tight, and cash turns over fast enough to fund the next job without borrowing.
- 30 to 45 days — workable, common, and worth improving. Net-30 terms naturally push you into this band; the goal is to keep customers near the terms, not well past them.
- Over 45 days — a problem. You are financing your customers' operations with your own cash, and the risk of a balance never getting paid rises the longer it ages.
Two caveats. First, compare yourself to yourself over time before comparing to any benchmark — a DSO trending down month over month is a win regardless of the absolute number. Second, your payment terms set the floor: if you bill net-30, a DSO of 32 is basically customers paying on time, while a DSO of 32 on due-on-receipt invoices means people are dragging their feet.
Why DSO matters more than owners expect
The mistake is treating an unpaid invoice as money you have. You booked the revenue, the job is done, so it feels earned. But an invoice is a promise, not cash, and promises do not make payroll.
A high DSO quietly does three expensive things. It forces you to fund finished work out of your own pocket, which is why busy businesses still reach for a credit line. It raises the chance a balance goes bad, because the older an invoice gets, the less likely it is ever paid in full. And it hides trouble: revenue looks fine on the profit-and-loss statement while the bank balance tells a different, scarier story. DSO is the number that reconciles the two — it is the bridge between "we're profitable" and "we have cash."
Five ways to cut it
DSO comes down when you shorten every step between finishing the work and the money arriving. These are the levers, roughly in order of impact.
- Invoice the day the job is done — not at the end of the week. Every day between finishing and billing is a day added straight onto DSO, for free. Same-day invoicing is the single biggest lever most businesses ignore.
- Make paying effortless. A customer who has to write and mail a check pays slowly; one who can tap a link and pay in a minute pays fast. Remove every point of friction between the invoice and the payment.
- Collect deposits on larger jobs. Money you take before the work starts never enters accounts receivable at all, which mechanically lowers your DSO and de-risks the job.
- Chase overdue balances on a schedule. A polite reminder at day 3 past due, another at day 10, and a phone call at day 20 collects far more, far faster, than waiting until you happen to remember. Consistency beats intensity.
- Bill in progress on long jobs. For multi-week work, invoicing at milestones instead of one lump at the end pulls cash in throughout the job rather than all at the far end.
None of these change what you charge. They change when the money arrives — and that is the entire game with DSO.
Where CRMb fits
Every lever above is really a billing-and-collections workflow, and that is exactly the part of the business CRMb is built to tighten.
When a job wraps, you invoice straight off it — pulling the labor from your crew's real punched hours in Punch and the materials from inventory at their true average cost — so billing happens the day the work is done instead of piling up for a Friday-night catch-up. Every invoice carries a public share link at its own address, so the customer opens it, reviews it, and signs off in seconds with nothing to download and no account to create. That is the friction, gone. And Reports shows your receivables at a glance — what is outstanding, and how long it has been sitting — so overdue balances surface on a schedule instead of slipping your mind. The whole loop, from finished job to signed invoice to collected cash, lives in one place, which is what keeps DSO from drifting up while you are busy running the work.
FAQ
What is a good DSO for a contractor or service business? Under 30 days is healthy for most businesses that invoice after the work. 30 to 45 is common and improvable, and anything past 45 usually means you are financing your customers. Your own payment terms set the realistic floor — you cannot beat net-30 by much if that is what you offer.
How is DSO different from accounts receivable? Accounts receivable is a dollar amount — the total you are owed right now. DSO turns that amount into a speed: how many days, on average, it takes to collect it. Two businesses can be owed the same $40,000 but have very different DSOs depending on how fast their customers pay.
Does a lower DSO always mean a healthier business? Usually, but not always. A very low DSO can also mean you are only taking due-on-receipt work or refusing reasonable terms that would win larger jobs. The goal is a DSO that stays close to your stated terms, not the smallest possible number at any cost.
How often should I calculate DSO? Monthly is plenty for most service businesses, and the trend matters more than any single reading. A number that climbs three months running is a signal to tighten collections before it becomes a cash problem.
Can collecting deposits lower my DSO? Yes. A deposit taken before the job starts is cash that never enters accounts receivable, so it both improves cash flow and pulls your average collection time down. On larger jobs it also reduces the amount you are exposed to if a customer pays slowly.
Getting started with CRMb
DSO is the number that tells you whether your finished work is actually turning into money — and it comes down when billing is instant and paying is effortless. CRMb invoices straight off the completed job, sends a public link the customer can open and sign in seconds, and keeps every outstanding balance in front of you in Reports, so cash comes back faster and nothing ages in the dark.
Start a 14-day free trial and see how fast your next invoice gets paid.