Supplier early-payment discount: practical guide

What to prepare

• Gather supplier quotes, invoices, time records and the actual scope of the job or business decision.
• Separate revenue from VAT, direct costs from overheads, and profit from the timing of cash receipts.
• Use the same accounting period and currency for related inputs.

Understand the inputs

The calculation method

Annualised discount return = discount ÷ (1 − discount) × 365 ÷ days advanced. Net benefit deducts simple funding interest.

Worked example

Illustrative inputs and their result.

Example inputs

Invoice amount (€)

10000

Early payment discount (%)

2

Early payment term (days)

10

Normal payment term (days)

30

Annual funding rate (%)

8

Calculated example result

Net Benefit

€157.04

Annualised Discount Return Percent

37.24%

Early Payment Amount

€9,800.00

How to interpret the result

A profitable estimate can still create a cash shortfall. Read the cost and timing assumptions as well as the headline profit, price or return; the result is a scenario, not a sales forecast.

Keep the scope constant while changing price, volume, supplier cost or time. A lower-sales or higher-cost case helps show whether the decision depends on an optimistic assumption.

Common mistakes to avoid

• Do not confuse markup on cost with margin on selling price.
• Include work that is easy to miss, such as travel, setup, rework and administration, where the model supports it.
• Do not treat tax collected or an unpaid invoice as freely available cash.

Assumptions and sources

The annualised rate is not compound APR; contractual eligibility and available liquidity matter.

Related business guides

• Margin & markup pricing: practical guide
• Cost of goods sold: practical guide
• Break-even analysis: practical guide
• Irish corporation tax: practical guide
• Customer acquisition & value: practical guide
• Stock turnover & DSO: practical guide