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Last updated: September 22, 2026
Every finance team knows the feeling: an invoice sits at 90 days, then 120, then someone finally writes it off and the revenue you already booked quietly disappears. The bad debt ratio is the metric that tells you how often that happens, how much it costs, and whether your credit and collections process is getting better or worse. This guide covers the formula, realistic benchmarks for B2B companies, the accounting behind the number, and a practical playbook for bringing it down without strangling sales.
Table of contents
- What is the bad debt ratio?
- Bad debt ratio formula (with a worked example)
- Bad debt ratio benchmarks for B2B
- Bad debt ratio vs. bad debt expense
- Why the ratio creeps up (and where to look first)
- How to reduce your bad debt ratio
- FAQ
What is the bad debt ratio?
The bad debt ratio is the share of your credit sales that you ultimately fail to collect. It expresses written-off receivables as a percentage of net credit sales (or, in some variants, of total accounts receivable) over a given period. Where days sales outstanding tells you how slowly customers pay, the bad debt ratio tells you how much of what they owe never arrives at all.
That distinction matters because the two metrics can move independently. A company can have a comfortable DSO and still bleed cash through a handful of large accounts that default, or it can run a high DSO with almost no write-offs because customers pay late but always pay. The bad debt ratio isolates the permanent loss, which is why CFOs, credit managers, and lenders watch it closely.
Bad debt vs. doubtful debt
Accountants separate two states. Doubtful debt is a receivable that is overdue and at risk but not yet confirmed lost. Bad debt is the confirmed version: collection efforts are exhausted and the invoice is written off. The ratio counts only the second category, though the allowance you set aside for the first one is what keeps your balance sheet honest in the meantime.
Bad debt ratio formula (with a worked example)
The most common formula is:
Bad debt ratio = (Bad debts written off ÷ Net credit sales) × 100
Suppose a distributor books $12 million in credit sales during the year and writes off $96,000 in uncollectible invoices. The bad debt ratio is 96,000 ÷ 12,000,000 × 100 = 0.8%. Some teams prefer to divide by total accounts receivable instead of credit sales; that version answers a slightly different question (how much of what is currently owed will you lose?) and tends to produce a higher number. Pick one convention and stick with it so your trend is comparable quarter to quarter.
Three ways to estimate bad debt before it happens
Because the write-off usually lands months after the sale, GAAP asks companies to estimate expected losses in the same period as the revenue. Upflow's guide to bad debt expense lays out the three standard approaches:
| Method | How it works | Best for |
|---|---|---|
| Direct write-off | Record the loss only when a specific invoice is confirmed uncollectible | Small companies with rare bad debts; accepted by the IRS but not GAAP-compliant for material receivables |
| Percentage of sales | Multiply credit sales by your historical bad debt rate | Stable customer mix; simple period-end close |
| AR aging | Apply a rising uncollectible percentage to each aging bucket (for example 1% current, 4% at 30–60 days, 10% at 61–90, 30% beyond 90) and sum | Companies with meaningful AR balances that want a risk-weighted reserve |
The aging method is the most useful operationally because it doubles as a collections priority list. If you already read your accounts receivable aging report every week, you have most of the inputs.
Bad debt ratio benchmarks for B2B
There is no single "good" number, but the published data gives you guardrails. Atradius' 2025 Payment Practices Barometer for North America found that 43% of credit-based B2B sales in the US are overdue and that bad debts affect about 5% of long-overdue invoices; in Mexico, 41% of credit sales are overdue with bad debts at roughly 4%, and in Canada the figures are 44% and around 6%. Those percentages describe the long-overdue slice of receivables, not total credit sales, so they are a ceiling on what a poorly managed book can lose, not a target.
Measured against total credit sales, most B2B companies aim considerably lower. Emagia's glossary notes that many businesses target a ratio below 1%, that B2B sellers of high-value goods with rigorous credit checks often run below 0.5%, and that high-volume, low-margin industries may tolerate 2–3%.
Key takeaway
Benchmark against your own history and your closest peers, and watch the direction more than the absolute number. A ratio drifting from 0.6% to 1.1% over four quarters is a louder alarm than a stable 1.5% in a thin-margin distribution business.
Why the ratio depends on margin
The tolerance for bad debt is a function of gross margin. If you earn 60% gross margin, one written-off invoice wipes out the profit on roughly 1.7 similar sales. At 15% gross margin, that same write-off erases the profit on about 6.7 sales. This is why distributors, logistics companies, and wholesalers treat the bad debt ratio as a survival metric while software companies sometimes treat it as a footnote.
Bad debt ratio vs. bad debt expense
The two terms travel together but are not the same thing. Bad debt expense is the line on your income statement: the amount you recognize as an operating cost in the period, whether from actual write-offs or from topping up your allowance for doubtful accounts. The bad debt ratio is the normalized version, dividing that loss by sales so you can compare periods of different sizes and compare yourself with other companies.
Under the allowance method, the expense hits the income statement when you set the reserve, and the later write-off simply moves the invoice out of AR and draws down the allowance. Under direct write-off, the expense and the write-off are the same event. Either way, the ratio you report to leadership should use confirmed write-offs in the numerator, with the allowance tracked separately as a forward-looking indicator.
Why the ratio creeps up (and where to look first)
Bad debt is rarely random. In most B2B books it clusters in a few predictable places:
- Credit approved on autopilot. New accounts onboarded without a credit check, or limits that were never revisited after a customer's financial position changed. Tightening this is the subject of our guide to AI credit management for B2B orders.
- Late first contact. Invoices that nobody touches until they are 60 or 90 days past due. The odds of recovery fall sharply with age, which is exactly why the aging method assigns 30% or more to the oldest bucket.
- Disputes left open. A short payment or a pricing disagreement that sits unresolved for weeks often ends as a write-off, not because the customer could not pay but because nobody closed the loop.
- Concentration risk. A handful of large accounts representing an outsized share of receivables. One default moves the ratio more than a hundred small ones.
- Unreachable debtors. Wrong phone numbers, bounced emails, and contacts who left the company. If your team cannot reach the right person, the invoice ages by default.
Segment before you diagnose
A blended ratio hides the problem. Break write-offs down by customer segment, sales channel, invoice size, and the age at which first contact happened. Very often, one segment carries most of the loss, and the fix is a policy change for that segment rather than a company-wide crackdown.
How to reduce your bad debt ratio
Reducing bad debt is a process problem more than a personnel problem. The levers below are listed roughly in the order most finance teams find them broken.
1. Make credit decisions explicit
Every new account should have a documented credit limit, payment terms, and an owner. Review limits at least annually and automatically whenever payment behavior deteriorates, for example after two consecutive late payments. Sales teams push back on this, so tie the policy to data: show them the segment where bad debt is concentrated and the margin it destroys.
2. Contact early, and contact the right person
The single most controllable driver of bad debt is the age at first contact. A friendly reminder a few days before the due date, a firm follow-up the day after, and a phone call within the first two weeks recover far more than the same effort spent at day 90. Consistency is the hard part: manual follow-up degrades whenever the team gets busy. A structured cadence of automated payment reminders removes that dependency.
This is where AI collections agents have changed the economics. Darwin AI's collections worker, Rio, contacts every overdue account by WhatsApp, email, or voice from the first day past due, negotiates payment dates within the rules you define, confirms promises to pay, and escalates disputes and hardship cases to a human. Because it never skips a queue, invoices stop aging silently, which is the mechanism that keeps them out of the write-off column in the first place.
3. Track promises, not just calls
A collections team that measures activity (calls made, emails sent) will optimize for activity. Measure outcomes instead: promise-to-pay kept rate, cash collected as a share of what was collectible, and the age of the receivable at resolution. Our breakdown of the promise-to-pay kept rate explains how to instrument this without adding admin work.
4. Close disputes fast
Set a service level for dispute resolution, route disputes to the person who can actually decide (often sales or operations, not collections), and treat any dispute open longer than two weeks as a bad debt risk. Many "uncollectible" invoices were collectible right up until the customer gave up waiting for an answer.
5. Measure the right companion metrics
The bad debt ratio is a lagging indicator; by the time it moves, the money is gone. Pair it with leading indicators: the share of receivables over 60 days, right-party contact rate, and the collection effectiveness index. When those deteriorate, you have weeks to react before the write-offs arrive.
6. Review the allowance every close
If actual write-offs consistently exceed your allowance, your uncollectible percentages are stale and your financials are overstating receivables. If write-offs consistently come in under the allowance, your collections process has improved and the ratio you report to the board should reflect it. Either way, a quarterly review keeps the estimate honest and gives leadership an early signal.
Example
A regional building-materials distributor with a 1.4% bad debt ratio segmented its write-offs and found that 70% came from accounts opened in the previous 12 months with no credit review. Adding a five-minute credit check at onboarding and a reminder on day 1 past due, rather than day 30, brought the ratio under 0.7% within three quarters, without changing payment terms for existing customers. (Illustrative scenario.)
Stop invoices from aging into write-offs. Rio follows up on every overdue account from day one, so your team only handles the exceptions.
Meet Rio, the AI collections workerFAQ
What is a good bad debt ratio?
It depends on industry and margin. According to Emagia, many businesses aim for a ratio below 1%, B2B sellers with strict credit assessment often stay below 0.5%, and high-volume, low-margin industries may accept 2–3%. The trend over time matters more than any single figure.
How do you calculate the bad debt ratio?
Divide bad debts written off during the period by net credit sales for the same period and multiply by 100. Some companies divide by total accounts receivable instead; whichever denominator you choose, use it consistently.
What is the difference between bad debt ratio and bad debt expense?
Bad debt expense is the dollar amount recognized on the income statement for uncollectible receivables. The bad debt ratio divides that loss by sales to produce a percentage you can compare across periods and companies.
How common is bad debt in B2B?
Atradius' 2025 survey found that 43% of credit-based B2B sales in the US are overdue and that about 5% of long-overdue invoices end up as bad debt, with similar patterns in Canada and Mexico.
Does the bad debt ratio affect DSO?
Indirectly. Writing off an invoice removes it from receivables, which can lower DSO even though the company lost money. That is why the two metrics should always be read together.
