How do you respond to a client asking for a discount?

The phone rings. A major client wants a large order but asks for a 10% discount. The most common response is one of two: say yes out of fear of losing them, or say no by gut feeling. In both cases, a fundamental piece of data is missing: how much margin remains after the discount?

With the contribution margin, the answer comes in 5 minutes. No complex spreadsheet needed: just three numbers.

What numbers do you need to decide?

To evaluate a discount, you need three pieces of information:

Current selling price — what you charge for that product or service
Variable costs — the costs that increase with each unit produced (materials, direct labor, subcontracting)
The requested discount — the percentage or amount the client wants

The contribution margin is the difference between selling price and variable costs. It's the contribution each unit sold makes toward covering fixed costs and generating profit.

What happens to margins with a 10% discount?

A company sells a component for €100. Variable costs are €65 (raw material €40, direct labor €20, external processing €5).

Scenario	Price	Variable costs	Contribution margin	Margin %
No discount	€ 100	€ 65	€ 35	35%
10% discount	€ 90	€ 65	€ 25	28%
20% discount	€ 80	€ 65	€ 15	19%
35% discount	€ 65	€ 65	€ 0	0%

With a 10% discount, the margin drops from €35 to €25 per unit — a 29% reduction. To maintain the same total margin, volume must increase by 40%.

With a 20% discount, the margin is halved. At 35%, you're working for free: the price only covers variable costs and contributes nothing to fixed costs.

This is why revenue can grow while profit shrinks: discounts granted without analysis erode the margin on every unit sold.

The practical rule: how much extra volume is needed?

When you grant a discount, volume must compensate for the lost margin. The formula is simple:

Required volume increase = Discount / (Current margin % – Discount)

In the previous example, with a 35% margin and a 10% discount:

10% / (35% – 10%) = 40%

To maintain the same total margin with a 10% discount, you need 40% more units. The question becomes: will the client actually order 40% more? If the answer is no, the discount doesn't make sense.

When does a discount make sense?

Not every discount is a loss. There are situations where accepting is the right choice:

Filling production capacity — if machines are idle, even a reduced margin is better than no margin, as long as the price covers at least variable costs
Entering a new market — a launch discount can be an investment, if it's temporary and planned
Retaining a strategic client — but only if the overall volume generates an adequate total margin

The key is always the same: know the numbers before deciding. If the full cost of the product isn't known, any discount decision is a gamble.

How to structure a sustainable discount policy?

Instead of deciding case by case, a more solid approach involves:

Calculate the contribution margin for your main products — starting from the real cost
Set a minimum threshold — below which margin percentage you won't go, regardless of the client
Establish volume-based discount tiers — the discount increases only if volume justifies it
Document and review — every discount granted should be recorded and reviewed quarterly

This isn't a complex process. A sheet with the 5 essential numbers kept up to date is enough to always have a clear picture.

In summary

A discount is neither good nor bad. It's a decision that should be made with numbers in front of you, not by instinct. The contribution margin is the tool that turns a stressful negotiation into an informed choice.

Those who already have a clear view of their margins — thanks to a controller or a management dashboard — can respond to any discount request in minutes, with confidence.

The price list guide explains how to build and maintain a price list based on real costs and target margins.

Want to build a discount policy based on real numbers? Get in touch for a no-commitment conversation, or learn about our strategic consulting.