A customer’s sales total does not tell you how profitable the relationship is. Some customers order straightforward work and pay promptly. Others require repeated revisions, urgent delivery, extensive support or substantial funding while invoices remain unpaid.
In this article
- Separate sales by customer or project
- Allocate the related costs
- Include staff time and rework
- Review pricing and delivery choices
Customer profitability analysis combines revenue with the resources used to earn it. Project analysis does the same for a defined piece of work. The objective is to understand the economics and make better decisions, not automatically dismiss every customer whose report looks weak.
Choose the question and unit of analysis
Decide whether you are reviewing a customer, contract, project or service line. Give each a clear reference so invoices, credits, time and purchase costs can be connected consistently.
Set the reporting period and recognise the stage of completion. Comparing the full cost of an unfinished project with only its initial invoice can produce a misleading loss. Explain whether the review concerns completed work, the latest estimate to completion or a period’s trading result.
Start with a small pilot if the records lack detail. Reviewing five significant completed projects can expose useful patterns without pretending the entire historical customer base is already measured accurately.
Capture the costs that change the answer
Direct materials, subcontractors and identifiable delivery time are common starting points. Also investigate rework, travel, returns and customer-specific support. Record actual activity rather than allocating every cost solely according to revenue.
Shared overheads require a documented approach. Rent and management time cannot always be traced exactly to one customer. Show direct contribution separately from any allocated full-cost result so users understand which figures are observed and which depend on assumptions.
| Cost or demand | Evidence to collect |
|---|---|
| Delivery labour | Time records with job reference |
| Materials and external work | Supplier invoices and purchase allocation |
| Changes and rework | Job notes, approvals and repeat visits |
| Customer support | Ticket, meeting or account-management records |
| Credits and returns | Linked sales adjustments |
| Funding burden | Payment history and collection activity |
Unrecorded owner time can matter commercially even where no additional wage payment occurs. Describe that resource use clearly without confusing a management estimate with an actual accounting expense.
Compare two illustrative projects
Illustrative example: project A earns £12,000 revenue and uses £7,000 of identifiable delivery resources, leaving £5,000 before shared overheads. Project B earns £15,000 but uses £11,500 of delivery resources, leaving £3,500 before shared overheads.
Project B has higher sales but contributes less at this stage. Its delivery record shows extra site visits and late specification changes. The next question is whether those demands were included in the agreement, separately chargeable or avoidable through a better process.
The figures are invented and exclude VAT. They do not establish a universal target or a quoted charge. They show why ranking customers by turnover can conceal where the business earns its margin.
Check the explanation before acting
Investigate incomplete time entries, materials posted to the wrong job and costs arriving after project completion. Confirm that credits and cancelled work are included. A weak allocation system can make the best-run project appear unprofitable.
Speak to delivery and sales colleagues together. They may identify strategic value, recurring follow-on work or temporary onboarding costs. These factors deserve explicit consideration rather than being used as an unmeasured excuse for every weak result.
Separate the customer’s behaviour from the business’s own delivery failures. Rework caused by poor internal quality should not automatically be attributed to a demanding customer.
Choose a practical commercial response
Possible actions include clearer scope, change approvals, different scheduling, a revised service arrangement or an updated quote for future work. Negotiation may improve the relationship more effectively than an abrupt withdrawal.
Review resource capacity as well as margin. A lower-contribution job could use otherwise idle resources, while another could displace more valuable work. Consider that trade-off openly and avoid treating shared-cost allocations as a complete decision model.
Payment terms also matter. A sound-margin project can still create cash pressure if the business funds materials and labour long before collection. Link the review to a cash forecast.
Repeat the review and improve the records
Track whether agreed changes improve new work. Compare estimates with completed-project outcomes and use the difference to refine future planning. Keep assumptions visible so the next review can challenge them.
Discuss EPOS profit and loss support around customer or project detail that your records can support. Management accounts can then place those findings alongside capacity, overheads and the wider business result.