Onetribe is a consulting firm specialising in management reporting, controlling, and finance function transformation for mid-market companies in Central Europe. A company’s cost structure is the way total costs are classified by their nature, behaviour, and point of origin. It is not just an accounting concept — it is the foundation for decisions about pricing, investment, capacity, and efficiency.
The English-language market has extensive cost management content at two extremes: enterprise advisory from BCG , McKinsey , and Deloitte that assumes dedicated cost management functions and six-figure budgets, and generic “10 ways to cut expenses” articles aimed at sole traders. The critical middle ground — practical, structured cost analysis for growing companies with £1–50M revenue — is largely absent. This guide fills that gap.
Why Statutory Accounts Are Not Enough to Manage Costs
Most statutory P&L formats classify costs by nature: materials, services, personnel, depreciation, taxes. This tells leadership what the company spent, but not where and why.
A manufacturing company’s statutory P&L might show £3M in personnel costs. But which portion belongs to production, which to sales, which to administration? Without that split, cost management is impossible — leadership is managing the entire company as one black box.
The management P&L reclassifies costs by behaviour (fixed vs. variable), by responsibility (cost centres), and by contribution (segment profitability). It answers the questions that statutory accounts cannot: Which products earn their keep? Which departments are overspending? Where is the leverage?
Fixed vs. Variable Costs — Why the Classification Matters More Than It Appears
The distinction between fixed and variable costs is taught in every finance course. In practice, most mid-market companies classify incorrectly — and the errors compound through every downstream analysis.
Common Classification Errors
| Cost | Often Classified As | Actually Behaves As | Why It Matters |
|---|---|---|---|
| Warehouse rent | Fixed | Fixed (correct) | — |
| Production overtime | Fixed (part of payroll) | Variable | Understates variable cost, overstates contribution margin |
| Sales commissions | Fixed (part of personnel) | Variable | Distorts break-even calculation |
| Delivery costs | Variable | Step-fixed (own fleet) | Creates false linearity in cost models |
| IT licences (per-user) | Fixed | Variable with headcount | Hides cost driver; appears uncontrollable when it is not |
The consequence of misclassification: contribution margin calculations are wrong, break-even points are wrong, and pricing decisions are made on incorrect data.
The Management P&L — Seeing What Statutory Accounts Hide
A management P&L restructures costs to show the path from revenue to profit through controllable layers:
| Line | Example (£10M company) | What It Shows |
|---|---|---|
| Revenue | £10,000,000 | Total sales |
| − Variable costs | £5,800,000 | Costs that scale with volume |
| = Contribution margin | £4,200,000 (42%) | What each sale contributes to covering fixed costs |
| − Direct fixed costs | £1,600,000 | Fixed costs attributable to specific products/segments |
| = Segment margin | £2,600,000 (26%) | True profitability by product/customer/channel |
| − Overhead / indirect costs | £1,800,000 | Costs that support the business but are not directly attributable |
| = Operating profit | £800,000 (8%) | Bottom-line profitability |
This structure reveals what statutory accounts cannot: which segments earn their contribution margin and which depend on cross-subsidy from stronger segments.
Cost Centre Structure — Designing Accountability Into the Organisation
Without cost centres, nobody is accountable for costs. With poorly designed cost centres, the reporting creates noise rather than insight.
Four Steps to Build a Cost Centre Structure
Step 1: Align cost centres with organisational responsibility. Each cost centre should have one clear owner — a person accountable for the costs incurred. If three managers share responsibility for a cost centre, nobody is accountable.
Step 2: Separate production, sales, administration, and management. At minimum, a mid-market company needs these four cost centre groups. Within each, subdivide by function or location if the business warrants it.
Step 3: Keep it granular enough to see, simple enough to manage. A £5M company does not need 40 cost centres. Eight to twelve is typically sufficient. Each one should be large enough to be meaningful and small enough to be controllable.
Step 4: Map every general ledger account to one cost centre. No cost should fall into “unallocated.” If a cost cannot be assigned to a centre, the structure needs adjustment.
Overhead Costs — The Invisible Margin Eroder
BCG (2025) found that within the same industry, overhead (non-production) costs as a percentage of revenue range from 15% to over 40%. This is not a scale effect — it reflects structural differences in how companies manage their cost base.
APQC benchmarks confirm the gap: top-quartile companies spend 1.2% of revenue on the finance function alone, versus 2.8% for the bottom quartile. The difference accumulates across every support function.
Most mid-market companies do not track overhead by cost centre. The result: overhead grows incrementally — a new licence here, a contractor there — and nobody sees the aggregate effect until margin compression becomes visible in the annual accounts.
What to do: Track overhead by cost centre with monthly reporting against budget. Set a threshold (e.g. overhead must not exceed 25% of revenue) and review quarterly. Overhead that is measured and owned tends to stabilise; overhead that is invisible tends to grow.
Break-Even Analysis — Beyond the Textbook
The textbook break-even formula (fixed costs ÷ contribution margin per unit) works for a single-product business. Mid-market companies with multiple products, segments, and channels need a multi-dimensional view:
- By product line: Which lines cover their direct fixed costs? Which depend on cross-subsidy?
- By customer segment: What volume does each segment need to contribute positively?
- By channel: Does the direct sales channel break even independently, or does it depend on distribution?
Break-even analysis becomes a decision tool when it answers the question: “What happens to profitability if we lose this product line / this customer / this channel?” That question connects directly to profitability analysis and scenario planning.
Four Steps to Better Cost Management
1. Build a Management P&L
Reclassify statutory costs into contribution margin format. Separate variable from fixed, direct from indirect. This single step transforms cost visibility.
2. Design and Implement Cost Centres
Assign every cost to a responsible owner. Report monthly. Compare against budget. This is where variance analysis connects to cost management.
3. Identify Your Top Cost Drivers
Not all costs deserve equal attention. Identify the five to ten factors that drive 80% of your cost base. This is the subject of the companion article on cost driver identification .
4. Benchmark and Set Targets
Compare your cost structure to industry benchmarks. Horvath (2025) found that 90% of CxOs rate cost and profit structure improvement as their top priority — but only 48% of cost-saving targets are achieved (BCG ). The gap is execution, not intention. Setting realistic, measured targets closes it.
Frequently Asked Questions
What is the difference between a statutory P&L and a management P&L? A statutory P&L classifies costs by nature (materials, personnel, depreciation) as required by accounting standards. A management P&L classifies costs by behaviour (variable/fixed) and by responsibility (cost centres/segments), enabling leadership to see where profit is created and where costs are controllable.
How many cost centres should a mid-market company have? For a company with £5–20M revenue, eight to twelve cost centres typically provide sufficient granularity without creating reporting overhead. Each centre should have one accountable owner and be large enough to be meaningful.
What percentage of revenue should overhead represent? It varies by industry and business model. BCG data shows overhead ranges from 15% to over 40% within the same industry. As a starting point, benchmark against publicly available industry data and set a target. The critical step is measuring and tracking — not the specific number.
Do I need special software for cost structure analysis? Not initially. A well-structured Excel model with a management P&L, cost centre reporting, and contribution margin analysis is sufficient for most mid-market companies. When the number of segments, products, or reporting dimensions grows beyond Excel’s practical limits, consider BI tools or reporting automation .
Where This Fits in Our Expertise
Cost structure analysis is part of the Performance Analysis pillar at Onetribe. It provides the cost dimension that complements profitability analysis and variance analysis . Without understanding the cost structure, leadership cannot interpret variances, set meaningful targets, or make informed pricing decisions.
Further Reading
- Cost Drivers — How to Identify What Really Drives Your Costs — the companion guide to this article
- Profitability Analysis Fundamentals — which products and customers actually earn money
- Variance Analysis — A Practical Guide — understanding why costs deviate from plan
- Management Reporting Framework — the reporting structure that presents cost data
- Financial Data Governance — data quality that cost analysis depends on
- Performance Analysis — Our Expertise — how we approach performance analysis
- Glossary: Cost Structure | Fixed vs. Variable Costs | Contribution Margin | Cost Driver | Cost-Volume-Profit Analysis
Sources
- BCG — Cost Management 2025 — only 48% of cost targets achieved; overhead 15–40% within same industry; cost leaders outperform by 9pp TSR
- Horvath — CxO Priorities 2025 — 90% of CxOs rate cost/profit structure improvement as top priority
- McKinsey — Cost Complexity — volume, structural, and executional driver taxonomy
- Deloitte — 1% saving in variable costs improves operating profit by 6.7%
- Roland Berger — product cost optimisation delivers up to 40% savings
- APQC — top-quartile finance function: 1.2% of revenue vs. 2.8% bottom quartile
- CIMA/IMA — ABC improves cost accuracy 15–25%; adoption below 30% at mid-market
- EY — Cost Transformation — sustainable cost management embedded in operating model
Martin Duben is CEO of Onetribe — a consulting firm specialising in management reporting, controlling, and finance function transformation for mid-market companies in Central Europe. With over 15 years of experience, he helps CFOs and business owners build information systems that support decision-making. Contact: onetribe.team .