Key Points
- DPO equals trade payables divided by cost of sales, multiplied by 365; a rising figure signals the entity is taking longer to pay suppliers.
- A sudden year-on-year increase in DPO can indicate cash flow stress, undisclosed supplier finance arrangements, a change in payment terms, or delayed invoice processing.
- Mid-market European entities typically report DPO between 30 and 70 days depending on sector and country payment culture.
- Auditors use DPO in ISA 520 analytical procedures to test the completeness of trade payables at the reporting date.
What is Payable Days / DPO?
You're reviewing the payables balance at year-end and it's jumped 35% with no corresponding increase in purchases. Before you write a SALY expectation and move on, that gap is exactly the kind of signal ISA 520 analytical procedures are designed to catch.
DPO translates the trade payables balance into a time measure: how many days of purchases remain unpaid at the reporting date. The standard formula divides the closing trade payables balance by cost of sales (or purchases, where available) and multiplies by 365. Some practitioners use average payables across the period rather than the closing balance, particularly when the business is seasonal. Check which version management uses and whether it's consistent with prior periods.
ISA 520.5 requires the auditor to design analytical procedures as risk assessment procedures. A DPO that has moved from 45 days to 72 days year-on-year is worth tracing. It could mean the entity renegotiated payment terms with suppliers, or it could mean the entity has entered a reverse factoring programme that IAS 7 .44A now requires to be disclosed. The 2024 amendments to IAS 7 (supplier finance arrangements) introduced specific disclosure requirements because such arrangements can obscure the true level of trade payables by transferring the obligation to a financial institution without changing the balance sheet line.
On the balance sheet, trade payables sit within current liabilities under IAS 1.69 . If an entity reclassifies supplier finance liabilities from trade payables to borrowings, the reported DPO drops and the debt-to-equity ratio rises. Evaluate whether the classification reflects the substance of the arrangement per IAS 1.70 .
Worked example: Fernández Distribución S.L.
Client: Spanish wholesale distribution company, FY2025, revenue €34M, IFRS reporter. Fernández purchases consumer goods from manufacturers and resells to independent retailers across Iberia. Cost of sales for FY2025 is €26.8M.
Step 1 — Extract trade payables and calculate DPO
Fernández reports trade payables of €5.9M at 31 December 2025. DPO equals €5.9M divided by €26.8M, multiplied by 365, producing 80.3 days.
Step 2 — Compare to the prior year
In FY2024, trade payables were €4.1M on cost of sales of €25.2M, producing DPO of 59.4 days. The increase of 20.9 days (35%) requires investigation under ISA 520.7 .
Step 3 — Investigate the movement
Enquiry with management reveals that Fernández entered a supplier finance programme with Banco Santander in May 2025. Under this arrangement, participating suppliers receive early payment from the bank, and Fernández settles with the bank at extended terms (90 days instead of the original 45-day supplier terms). €2.4M of the closing trade payables balance relates to amounts owed under this programme.
Step 4 — Assess classification and completeness
IAS 7 .44B requires Fernández to disclose the terms and conditions of its supplier finance arrangements, including extended payment terms. The auditor evaluates whether the €2.4M should remain in trade payables or be reclassified to borrowings. Under the arrangement, Fernández's obligation shifts to the bank and the payment terms have been extended well beyond normal trade credit. The bank also charges a financing fee. If the substance is a financing arrangement, reclassification to borrowings would reduce trade payables to €3.5M and DPO to 47.7 days, which aligns with the historical trend.
Conclusion: the reported DPO of 80.3 days is only meaningful after the auditor resolves the classification of the supplier finance balance; if reclassification applies, the adjusted DPO of 47.7 days is consistent with prior periods and the payables balance is defensible.
Why it matters in practice
Teams accept an increase in DPO without enquiring about supplier finance arrangements. IAS 7 .44A (effective January 2024) requires disclosure of supplier finance programmes precisely because they distort the payables balance. An audit file that documents DPO analytical procedures but contains no enquiry about reverse factoring misses the point of the ratio analysis. In our experience, this is one of the most common review notes on mid-market group audits.
Completeness testing on trade payables frequently relies on ticking and bashing the supplier statement reconciliation without investigating payables that should have been recorded but were not. ISA 505 .A1 identifies supplier confirmations as one form of external evidence, but the more effective procedure is a search for unrecorded liabilities at the reporting date (goods received but invoice not yet received). A clean DPO trend does not substitute for that procedure. Nobody enjoys the unrecorded liabilities search, but it's the test that actually catches understatement.
Payable days vs. receivable days / DSO
| Dimension | Payable days (DPO) | Receivable days (DSO) |
|---|---|---|
| What it measures | Average time to pay suppliers | Average time to collect from customers |
| Formula | Trade payables ÷ cost of sales × 365 | Trade receivables ÷ revenue × 365 |
| Direction of concern | Rising DPO may signal cash flow stress or undisclosed financing | Rising DSO may signal credit risk or revenue recognition issues |
| Completeness vs existence | Auditor tests completeness: are all payables recorded? | Auditor tests existence: are receivables real and collectible? |
| Cash conversion cycle link | DPO reduces the cash conversion cycle (the entity funds itself with supplier credit) | DSO increases the cash conversion cycle (the entity waits for customer payment) |
These two ratios move in opposite directions within the cash conversion cycle. An entity that extends its DPO while holding DSO constant frees cash. When DSO is rising while DPO is falling, the entity is funding its customers from its own cash reserves. ISA 570 .A3 would flag that pattern as a liquidity indicator.
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Frequently asked questions
How do I test the completeness of trade payables using DPO?
Compare DPO at the reporting date to the prior year and to interim periods. A decline in DPO at year-end followed by a spike in January suggests payables were understated at the reporting date. ISA 520.7 requires the auditor to investigate unexpected relationships, and a sudden drop in DPO at the balance sheet date while purchase volumes remained stable is exactly that kind of signal.
Do supplier finance arrangements change how I audit trade payables?
Yes. IAS 7.44A-44E (effective for periods beginning on or after 1 January 2024) requires the entity to disclose the carrying amount of liabilities within supplier finance programmes and the payment terms. Obtain the programme agreements and assess whether the liabilities should be classified as trade payables or borrowings, then test the disclosures against IAS 7.44A-44E. A supplier finance programme that shifts two million euros or more of payables into extended terms is a significant transaction under ISA 315.A92.
What is a normal DPO for European companies?
We've seen DPO range widely across sectors. Wholesale distribution entities in Southern Europe often report 50 to 75 days reflecting longer payment cultures. Northern European manufacturing firms typically pay within 30 to 45 days. The EU Late Payment Directive (2011/7/EU) sets a default maximum of 60 days for business-to-business transactions unless expressly agreed otherwise. Benchmark against sector peers and the entity's own contractual terms rather than a single threshold.