How to check receivables and days sales outstanding

Define the collection question before calculating a ratio

Receivables research starts with a specific question: how much recorded business is still waiting to become cash, and what explains the change? Days sales outstanding, usually shortened to DSO, can help organize that question. It cannot identify late invoices, customer disputes or accounting problems by itself. This guide builds a small external worksheet so you can reproduce a calculation and state its limits.

Begin with the company you are researching in ThesisMemo and follow available filing or research source links to the original report. Check the issuer, filing date and reporting period. Keep the worksheet in your own spreadsheet or document; this tutorial does not assume that ThesisMemo offers an automated DSO calculator or invoice-level collection records.

Separate three items in your notes: the reported receivable balance, the company's own definition of its collection metric, and your calculation. If the company does not disclose a needed input, mark it unavailable. A number calculated with a substitute denominator should carry that qualification wherever you later use it.

Copy the definition, not just the reported number

Published DSO measures do not necessarily use the same numerator. Kimball Electronics' annual report for the year ended June 30, 2026 defines its measure using monthly-average trade accounts and notes receivable divided by average daily net sales. Its contract-asset-days measure is separate. That definition tells you which balances to look for before attempting to reproduce its calculation.

Quanta Services' annual report for 2025 uses a different approach: current accounts receivable net of allowance, including retainage and unbilled balances, plus contract assets and less contract liabilities, divided by average revenue per day during the quarter. These are examples of disclosed methodologies, not a comparison of the two companies' collection performance or a claim about their newest results.

In your worksheet, create fields for balance scope, averaging method, sales basis and interval. Add the source section beside each field. Do not compare two reported DSO figures until those fields are understood. If you build a common alternative calculation, label it as your estimate rather than replacing either company's disclosed measure.

Work through a matched-period example

The following example is entirely hypothetical. Harbor Components reports 180 million dollars of credit sales during a 90-day quarter. Opening gross trade receivables are 80 million and closing gross trade receivables are 100 million. Assume that both balances relate to the same business and currency, and that there are no acquisitions, disposals or accounting-scope changes.

For this exercise, define estimated DSO as the two-point average gross trade receivable balance divided by credit sales, multiplied by days in the interval. The average is (80 + 100) / 2 = 90 million. Average daily credit sales are 180 / 90 = 2 million. Estimated DSO is therefore 90 / 2 = 45 days. Keep the word estimated because a two-point average does not describe every day's balance.

Using only the closing balance gives 100 / 2 = 50 days. That five-day difference comes from a method change, not additional evidence that customers paid later. Preserve both labels if you show both calculations. Before using a real issuer's reported DSO, return to its definition to see whether it uses period-end, monthly-average or another balance basis.

Test how the denominator changes the answer

Continue the hypothetical example. Suppose Harbor also has 20 million dollars of cash sales, bringing total quarterly sales to 200 million. The worksheet's credit-sales definition still uses 180 million. If only total sales were available, dividing the same average receivables of 90 million by 200 million and multiplying by 90 days would give 40.5 days.

That result is 4.5 days below the credit-sales estimate of 45 days. It is an approximation based on a broader denominator. Record the substitution explicitly instead of presenting the difference as an improvement in collections. When a company itself defines DSO using net revenue, use that stated definition for reproducing its reported figure and keep your alternative calculation separate.

Also match the interval. A quarterly balance comparison paired with nine-month cumulative sales produces an incoherent ratio unless you intentionally define and explain that method. Check actual fiscal dates rather than assuming every quarter contains exactly 90 days. The round interval here makes the arithmetic transparent; it is not a universal reporting convention.

Reconcile the balance movement before explaining it

Now assume Harbor's gross receivables have only two movements during the quarter: credit sales and customer cash collections. Under those deliberately simplified assumptions, opening receivables of 80 million plus 180 million of credit sales less collections equal closing receivables of 100 million. Collections are therefore 160 million dollars. The 20 million increase in receivables means some recorded sales remain uncollected at quarter-end.

Change one assumption: the company writes off 5 million dollars of receivables, and all other inputs stay the same. The bridge becomes 80 + 180 minus collections minus 5 = 100. Collections are now 155 million. A write-off reduces the receivable balance without collecting cash, so ignoring it would overstate collections in this example.

A real filing may contain other movements or insufficient detail to construct this bridge. Do not manufacture a balancing number. Search the notes for the disclosed explanation and retain any unexplained difference. The purpose is to identify what evidence is missing, not to turn a simplified teaching equation into an assertion about an issuer's actual receipts.

Keep gross balances, allowances and aging distinct

For another hypothetical snapshot, assume Harbor has gross receivables of 100 million dollars and an allowance of 4 million. Net receivables are 96 million. If you substitute 96 million for 100 million in the quarter-end version of our ratio while daily credit sales remain 2 million, the result becomes 48 days instead of 50. That change is entirely due to the balance basis.

It does not show that cash arrived two days sooner. Give gross and net amounts separate rows and identify which one the issuer uses. When an allowance changes, read the accompanying disclosure before assigning a cause. A balance-sheet adjustment and a customer payment should not become interchangeable explanations in your research note.

Likewise, a 45-day DSO estimate does not mean every invoice is 45 days old, nor that every customer pays late after 45 days. It is an aggregate ratio built from selected inputs. If the report discloses an aging schedule or discusses payment terms, read that evidence separately. Without it, the worksheet cannot establish how much is overdue or which customers are responsible.

Turn the calculation into a useful next checkpoint

Finish with a short, reproducible observation. In our first scenario, estimated average-balance DSO is 45 days using gross trade receivables, credit sales and a 90-day interval. The closing-balance version is 50 days. Under the no-write-off bridge, estimated collections are 160 million dollars. Those statements preserve the method and assumptions rather than claiming that one ratio explains business quality.

For a real company, make a comparison across matched periods using the same definition, then investigate any material change. Ask whether the source describes sales timing, payment terms, a changed customer mix or a transaction affecting balances. Those are research questions, not presumed explanations. A faster-growing receivable balance can identify a question worth pursuing without proving a particular cause.

Save the filing URL, section, input values, formula and unresolved issue together. On your next ThesisMemo visit, check the source and review dates before updating the record. Its methodology page distinguishes reporting periods, publication dates and review dates, and notes limits in coverage and verification. A subsequent filing may resolve the question; a refreshed page date alone does not.

Before closing the worksheet, verify four things: the receivable basis matches your definition, the sales interval matches the day count, the arithmetic can be reproduced, and your written conclusion is no stronger than the available disclosure. That compact review makes the work reusable when the next quarter arrives.