AI Pricing Reviews: Markup and Margin Use Different Bases

An AI-assisted pricing sheet says a service costs £100 to deliver. Add 25%, charge £125 and call the result a 25% margin. The calculation has added the right amount for a 25% markup. The label describes something else.

The difference matters when reviewing a proposal, approving a discount or comparing two service designs. Both percentages begin with the same gap between selling price and cost. They divide that gap by different numbers. A polished explanation can conceal the switch unless the calculation keeps its denominator visible.

Name the base before quoting the percentage

Xero’s guide to markup and margin, published on 23 July 2026, distinguishes markup based on cost from margin based on selling price. In formula form, markup is the difference between price and cost divided by cost; margin is that difference divided by price. Multiply each result by 100 to express it as a percentage.

For a £100 cost and £125 price, the difference is £25. Dividing £25 by £100 gives a 25% markup. Dividing £25 by £125 gives a 20% margin. Nothing about the transaction changed. Only the question changed: how much was added relative to cost, or how much of revenue remains after that cost?

A business report should also identify the cost being subtracted. Calling a percentage a margin does not establish that every expense has been included. Gross, contribution and net measures need appropriate definitions; they should not be treated as interchangeable labels.

A fictional AI-assisted service

Imagine a small studio preparing a reviewed content package. For an illustrative delivery model, assume £20 of AI usage, £60 of human review and £20 of other production work per package. The included delivery cost is £100. These are invented amounts, not market rates or a report about an actual studio.

The model leaves shared overheads outside that £100 and ignores tax for the arithmetic illustration. The £25 remaining from a £125 sale is therefore an amount left after the specified delivery costs. It should not be presented as the studio’s net profit.

ACCA’s technical guidance on pricing distinguishes different cost bases. Its marginal-cost example explains that the contribution from sales must still cover fixed costs before the business makes a profit. It also identifies costs, customers and competitors as influences on pricing decisions.

For the hypothetical studio, I would keep a short definition beside the figures: this calculation covers the stated package-delivery activities; shared overheads are reviewed separately. That makes the report’s scope visible without pretending the example is a complete accounting model.

A target margin needs a different calculation

Suppose the studio’s planning exercise asks what price would leave 25% of revenue after the same £100 included cost. Adding 25% to £100 will not achieve that result, as the first example showed.

If 25% of the price is to remain, the £100 cost must account for the other 75%. Divide £100 by 0.75. The unrounded price is £133.333…; a displayed price of £133.33 is approximately the result, with a small rounding difference.

That is a worked calculation under an assumed target. It is not a recommendation that this studio should charge that price. Whether customers want the package at that amount remains a separate commercial question.

An AI-assisted spreadsheet should show whether its input is a markup on cost or a margin on revenue. A column headed merely “profit %” leaves the intended calculation unresolved. Rename it before relying on its output.

A discount changes the remainder disproportionately

Now return to the original £125 price and £100 included cost. Apply a 10% discount to the selling price. The new price is £112.50, leaving £12.50 after the unchanged included delivery costs.

The price fell by £12.50, which is 10% of £125. The remainder also fell by £12.50, but that is half of the original £25 remainder. Its margin on revenue is now about 11.1%, calculated as £12.50 divided by £112.50.

These figures do not predict the result of a real promotion. They hold the package and its included costs constant. If a promotion changes purchase volume, delivery effort or other costs, those assumptions need their own calculations.

For an approval discussion, I would show the revised price, included cost and amount remaining together. A discount percentage alone does not communicate what has happened to the amount available for the expenses excluded from this model.

A cheaper component is not the whole cost

Consider a different revision: the selling price stays £125, but extra review work increases the included delivery cost from £100 to £110. The remainder becomes £15, and the margin on that cost basis becomes 12%. A cheaper AI component would not establish an overall improvement if other included costs rose enough to offset it.

MaryChuks’ guide to measuring savings across the whole AI workload examines that related problem. A component discount needs to be connected to the operating pattern and the wider calculation.

For the studio, define the unit being priced: one draft, one accepted package or a package including an agreed revision. If cost is estimated per draft while revenue is earned per accepted package, the comparison needs to account for that difference. Ask the report writer to explain the route from work performed to the charged deliverable.

Give the pricing review a clear brief

My proposed review questions for an AI-assisted pricing sheet are:

• What is the priced unit, and what work does it include?
• Which costs are included, which are excluded and why?
• Is the requested percentage markup on cost or margin on revenue?
• Can the calculation reproduce the £100-cost, £125-price example correctly?
• What happens to price and the remaining amount after a discount or cost increase?
• Which assumptions come from records, and which remain estimates?

Keep the arithmetic check separate from the commercial decision. A formula can be correct while the cost estimate is incomplete or the assumed demand is unsupported. Identify who owns each assumption and what evidence would justify changing it.

The leadership task is to make the figure interpretable. State the cost basis, show the amount remaining and name the denominator. Then a reader can see what the percentage establishes—and which business questions still need answering.

Sources

• Xero UK: Markup vs margin — published 23 July 2026.
• ACCA: Pricing 2 — Practical aspects — undated technical guidance, checked 4 November 2026. All studio figures are illustrative assumptions.