What it means
Every unpaid supplier invoice is a short-term, interest-free source of funding, and the average payment period measures how much of that funding the business is using. It is also called days payable outstanding, and it is one of the three components of the cash conversion cycle alongside stock days and collection days.
The measure matters because supplier credit is usually the cheapest working capital a business has. Stretching payment from 30 to 45 days on a large purchasing base can free up hundreds of thousands of dollars permanently, without any loan application or interest cost.
The limit is relationship risk rather than arithmetic. Suppliers respond to slow payment by tightening terms, withdrawing credit, deprioritising your orders or quietly raising prices, and in a supply squeeze the slow payers are the ones left waiting.
The measure should therefore be read alongside how your suppliers actually behave, not just the number of days. The calculation normally uses cost of goods sold as the denominator because that approximates credit purchases, though total purchases is more accurate where stock levels move a lot.
As with receivables, an average of the opening and closing payables balance smooths out the distortion caused by a large payment run just before period end. The important nuance is early settlement discounts, which can make paying quickly the better financial decision.
Terms of 2/10 net 30, meaning a 2% discount for payment within 10 days rather than the full 30, are equivalent to a very high annualised return on the cash used, and a business with spare liquidity is usually better off taking them.
In practice
Real-world examples.
Example
A restaurant group negotiates payment terms with its main food supplier from 14 days to 30 days in exchange for consolidating orders. The change frees about $95,000 of working capital and removes the weekly scramble around payment runs.
Example
A construction subcontractor takes 68 days to pay its materials merchant. The merchant reduces its credit limit at the start of a busy season, forcing the subcontractor onto pro-forma terms that cost it a project deadline.
Example
An electronics importer with strong cash reserves deliberately runs a payment period of 12 days to capture early settlement discounts averaging 1.5%. On $8,000,000 of purchases that is $120,000 a year of pure margin.
Think of it
“Average payment period is how long you take to pay your bills-longer preserves cash but may hurt relationships.
Formula
Calculation
Average Payment Period = (Average Accounts Payable / Cost of Goods Sold) x 365 days.
A wholesaler reports cost of goods sold of $5,475,000 for the year and average accounts payable of $600,000.
Average daily cost of goods sold: $5,475,000 / 365 = $15,000 a day.
Average payment period: $600,000 / $15,000 = 40 days.
Supplier terms are 30 days, so the business is running 10 days beyond agreed terms, which is holding on to 10 x $15,000 = $150,000 of supplier money it should already have paid.
Now consider a supplier offering 2/10 net 30 on $1,000,000 of annual purchases. Paying 20 days early to take the discount saves 2% of the invoice, and the annualised cost of not taking it is (2 / 98) x (365 / 20) = 37.2% a year. Against an overdraft rate of 9%, borrowing to pay early is clearly worth it, so the business should shorten its payment period for that supplier even while lengthening it elsewhere.Case study
Seen in the real world.
Rowan Hill Provisions is a fictional food distributor used here as an illustrative example. Facing a cash squeeze, its finance team pushed the average payment period from 34 days to 61 days across all suppliers, which released roughly $520,000 of cash and made the quarterly numbers look considerably healthier.
Six months into this illustrative scenario, the consequences arrived together. Two suppliers moved the company to pro-forma terms, one withdrew a 3% volume rebate worth $84,000 a year, and a third prioritised competitors during a shortage, leaving Rowan Hill unable to fill orders for a key retail customer.
The fictional company eventually settled on a segmented policy: 30 days for the six strategic suppliers it could not afford to lose, 45 to 55 days for commodity suppliers with plenty of alternatives, and immediate payment where a settlement discount beat its cost of borrowing. The payment period settled at 44 days with the supplier relationships intact.
Watch out
Common mistakes.
- Treating a longer payment period as an unqualified win. Free supplier credit stops being free when it costs you rebates, priority in a shortage or a price increase at renewal.
- Applying one payment policy to every supplier. Strategic suppliers, commodity suppliers and those offering settlement discounts should be paid on different rhythms, not on a single blanket rule.
- Comparing the ratio across industries without adjusting. A supermarket paying in 45 days and a professional services firm paying in 45 days are in completely different positions, because their cost structures and supplier bases have almost nothing in common.
Questions
People also ask.
How does this differ from the average collection period?
Collection period measures how fast customers pay you, payment period measures how fast you pay suppliers, and the healthy pattern is collecting faster than you pay.
Should the calculation use cost of goods sold or total purchases?
Total purchases is more precise, but cost of goods sold is used more often because it is readily available in published accounts, and consistency between periods matters more than the choice itself.
Is it ever sensible to pay suppliers early?
Yes, when a settlement discount beats your cost of borrowing, or when early payment secures priority, better pricing or supply security from a supplier you depend on.
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