Collection Effectiveness Index (CEI): Formula and Benchmarks
The collection effectiveness index measures how much of your collectible AR you actually collected. Formula, worked example, benchmarks and how to improve CEI.
By the AccountsReceivable.ai team
July 2026 · 7 min read
The collection effectiveness index (CEI) measures what percentage of the receivables available to collect in a period you actually collected. The formula is beginning receivables plus credit sales, minus ending total receivables, divided by beginning receivables plus credit sales minus ending current receivables, times 100. A CEI of 100 percent means you collected everything that came due. Most healthy US B2B finance teams run somewhere between 80 and 90 percent, and anything below 70 percent points at a collections process that is not working.
CEI is the metric that survives a growth spurt. Days sales outstanding, the number most teams report, moves when sales move, so a good quarter can quietly make your collections look worse and a slow quarter can make a struggling team look competent. CEI compares what you collected against what was actually collectible, which is why credit managers and controllers use it to judge the collections function itself.
What is the collection effectiveness index formula?
Written out in full:
| Component | What goes in it |
|---|---|
| Beginning receivables | Total AR balance at the start of the period |
| Credit sales | Sales made on terms during the period, not cash sales |
| Ending total receivables | Total AR balance at the end of the period |
| Ending current receivables | The part of the closing balance that is not yet due |
CEI = (Beginning AR + Credit sales - Ending total AR) / (Beginning AR + Credit sales - Ending current AR) x 100
The numerator is what you collected. The denominator is what you could have collected, which is everything except the invoices that were not due yet at period end. Excluding current receivables is the whole trick: you should not be penalized for an invoice issued on the 28th with net 30 terms.
How do you calculate CEI with an example?
Take a distributor closing out a quarter:
- Beginning receivables: $1,400,000
- Credit sales for the quarter: $3,200,000
- Ending total receivables: $1,600,000
- Ending current receivables (not yet due): $1,150,000
Numerator: 1,400,000 + 3,200,000 - 1,600,000 = $3,000,000 collected.
Denominator: 1,400,000 + 3,200,000 - 1,150,000 = $3,450,000 collectible.
CEI = 3,000,000 / 3,450,000 x 100 = 87 percent.
So 87 cents of every collectible dollar came in. The missing 13 percent, $450,000, is sitting past due. That number is the useful part of the exercise. It converts a percentage into a dollar figure your CFO can react to, and it is usually the fastest way to get budget for fixing collections.
What is a good collection effectiveness index?
Read CEI against your own trend first and industry benchmarks second, because payment norms vary enormously by sector. As a general guide for US B2B:
| CEI | What it means | What to do |
|---|---|---|
| 95 to 100% | Excellent. Nearly everything collectible is collected | Protect it, watch for concentration risk in a few large payers |
| 85 to 94% | Healthy for most B2B sellers | Work the tail: the same handful of chronic late payers usually explains the gap |
| 75 to 84% | Slipping. Follow-up is inconsistent | Fix cadence and ownership before adding headcount |
| Below 70% | The collections process is not functioning | Structural fix needed: terms, credit screening, escalation, staffing |
Two caveats before you take that table to a board meeting. Sectors with long contractual terms, construction with retainage or logistics with net 60, will read lower without anything being wrong. And a single large customer paying two days after quarter end can swing a mid-sized company's CEI by several points, which is why the metric is far more useful as a 12-month trend line than as a single number.
CEI vs DSO: what is the difference?
They answer different questions, and reporting only one is how teams end up misreading their own performance.
| CEI | DSO | |
|---|---|---|
| Question it answers | Did we collect what was collectible? | How long does cash take to arrive? |
| Unit | Percentage | Days |
| Distorted by sales growth | No | Yes, heavily |
| Distorted by payment terms | Barely | Yes, net 60 always reads worse than net 15 |
| Best used for | Judging the collections team and process | Judging working capital and cash forecasting |
The practical rule: use DSO to talk to the CFO about cash and CEI to talk to the collections team about performance. If DSO is rising while CEI holds steady, you sold more on longer terms; the team is fine and the mix changed. If CEI is falling while DSO looks flat, collections is quietly deteriorating and growth is masking it. That second pattern is the one that hurts, because nobody notices until a quarter goes badly.
Why is my CEI dropping?
In most audits of a falling CEI, the cause is one of five things, and only one of them is genuinely about customers running out of money.
- Follow-up stops after the first automated reminder. The system sends one email at day 3 past due and nothing escalates. Most late invoices need three to five touches, and the later ones need to reach a person with authority, not the shared AP inbox.
- Disputes are parked, not resolved. An invoice contested over a missing PO number or a quantity mismatch stops being collectible in practice while it still counts against you. Getting the invoice matched back to the purchase order the customer approved is usually a five-minute job that sits for six weeks because nobody owns it.
- Credit was extended without screening. Accounts that were poor risks at onboarding show up as bad CEI a quarter later. This is a credit problem wearing a collections costume, and no amount of chasing fixes it. See setting a credit policy.
- Cash is collected but not applied. If payments sit unapplied, invoices look open when the money is already in the bank, and CEI understates reality. Check your unapplied cash balance before concluding the team is underperforming.
- A few large accounts changed behavior. One customer moving from net 30 to paying at 55 days can move the whole metric. Always decompose CEI by customer before you act on it.
How do you improve your collection effectiveness index?
CEI responds to process discipline faster than almost any other AR metric, because the denominator is fixed by your sales and the numerator is entirely about follow-up.
- Chase before the due date, not after. A short reminder three days before due converts a meaningful share of invoices that would otherwise age. It is the cheapest point of intervention you have.
- Set a fixed escalation ladder. Reminder, second reminder, phone contact, then a formal demand at agreed day counts, applied the same way to every account. Consistency matters more than the exact days. Our collection letter templates lay out the four standard stages.
- Segment by value. The top 20 percent of open balance deserves phone contact; the long tail should be fully automated. Treating both the same is how teams burn hours on $400 invoices while a $60,000 one drifts.
- Route disputes out of the collections queue within 24 hours. A disputed invoice needs a resolver, not another reminder. Tracking dispute age separately keeps it from poisoning your CEI silently.
- Measure it monthly and by collector. CEI reported once a year changes nothing. Monthly, split by owner and by customer segment, it becomes a management tool. Pair it with the other metrics in our AR KPI guide.
The teams that move CEI 10 points rarely do it by hiring. They do it by making sure every overdue invoice actually gets contacted, on a schedule, without depending on somebody remembering. That is exactly the work collections automation software takes over: it chases every overdue invoice across email, SMS and live AI phone calls, escalates on a fixed cadence, and applies the cash back to your ledger so the metric reflects reality.
Is CEI the same as the collection ratio?
Not quite, though the terms get used loosely. A basic collection ratio usually means collections divided by total sales or total receivables, which does not exclude invoices that were never due yet. CEI deliberately removes current receivables from the denominator so you are only measured on what was genuinely collectible. That single adjustment is why credit professionals treat CEI as the more honest read on collections performance, and why it belongs on your monthly reporting pack next to DSO, aging and bad debt.
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