Which customers earn their discount? Rank your top 10 by profit
Revenue rank is not profit rank. A one-hour, one-table ranking of your top 10 customers by profit left after discount and cost to serve shows who to keep, reprice or let go.
Revenue rank is not profit rank
Most owners list their customers by turnover. The list feels like a league table, but it ranks size, not earnings. A customer who takes 18% of your invoiced sales can leave under 8% of your profit once discounts and the cost of serving them are taken off.
Below is a worked example. The figures are for illustration only: ten customers, cost of goods at 62% of list price, and a cost-to-serve estimate (extra handling, rush orders, credit control, returns) for each.
| Customer | Invoiced (£k) | Discount | Profit left (£k) | Profit / invoiced |
|---|---|---|---|---|
| 2 | 332.5 | 5% | 103.5 | 31.1% |
| 4 | 240.0 | 4% | 77.0 | 32.1% |
| 1 | 352.0 | 12% | 74.0 | 21.0% |
| 7 | 145.5 | 3% | 46.5 | 32.0% |
| 5 | 180.0 | 10% | 28.0 | 15.6% |
| 3 | 255.0 | 15% | 24.0 | 9.4% |
| 6 | 154.8 | 14% | 23.2 | 15.0% |
| 10 | 75.2 | 6% | 21.6 | 28.7% |
| 8 | 110.4 | 8% | 21.0 | 19.0% |
| 9 | 89.0 | 11% | 10.0 | 11.2% |
Customers 3 and 9 bring 17.8% of invoiced sales and 7.9% of profit. Customers 2, 4 and 7 bring 37.1% of sales and 52.9% of profit. The average margin of 22.2% describes none of them.
Why this matters now
The squeeze is visible in the national numbers. The ONS producer price release for September 2026, published on 21 October 2026, shows materials and fuels bought by manufacturers 8.3% dearer than a year earlier, while factory-gate prices rose 4.6%. The ONS links both mainly to oil-related products. Input costs are running ahead of what firms are charging.
Make UK's Manufacturing Outlook for Q1 2026 says businesses are raising prices at the fastest pace since 2023, with energy and employment costs the main pressures. When costs rise faster than prices, the customers who already earn least are the first to turn loss-making. The Bank of England announces its next rate decision on 5 November 2026, so financing costs are also in play. That is a date, not a forecast.
The one-table method
Take one hour and build the table above for your top 10 customers by turnover.
- Start from invoiced sales, not list price. The discount is already inside it.
- Subtract the cost of goods or direct labour for what you actually shipped.
- Subtract an honest cost-to-serve: rush orders, small drops, returns, chasing payment. A rough estimate beats leaving the column blank.
- Rank by profit left, then sort each customer into one of three groups: keep, reprice, or let go.
In the example, customers 2, 4, 7 and 10 are "keep". Customers 1, 3, 5, 6 and 9 are "reprice", starting where price sensitivity looks lowest. Customer 9 is the candidate to let go if repricing fails. The result is direction, not measurement: it tells you where to look first, and the decision stays with you.
Why the principle holds
A peer-reviewed case study of a food manufacturer (Guerreiro, Bio and Merschmann, International Journal of Logistics Management) found that measuring cost-to-serve gives a fuller view of customer profitability than the classical approach. It is a single case, so it shows the method works, not how big the effect will be in your business. Its authors note that profit depends as much on the cost of serving customers as on the cost of producing goods.
Tips and tricks for this week
- Pull your last 12 months of invoices for the top 10 customers; it takes less than an hour.
- Put a number on cost-to-serve even if it is a guess, then refine it once.
- Reprice one customer, not all. Pick the one with the lowest profit left and the lowest sensitivity to price.
- Write down the review date before you send the new price.
- Check the table again after the Bank of England decision on 5 November.
To see this across your whole customer base, the Business Health Check is the next step. One change, one date.