Management Accounting for a Car Dealership or Garage: Tracking Margin by Department

A positive overall net result can mask a very different reality: a dealership losing money on new vehicles, compensating through the workshop, and funding the whole operation with manufacturer bonuses. Without analytical accounting, these imbalances remain invisible until a change in manufacturer policy or a drop in volume brings them to the surface. Departmentalisation is the only serious answer to the question every dealer or garage owner should be asking: where do we actually make money?

This approach is not required by French law, but it has become the industry standard, often formalised in the reporting demanded by manufacturers. It is also essential for any multi-activity dealership or garage director who wants to allocate resources intelligently and support sound management decisions.

For an overview of the sector as a whole, see our dedicated pages for car dealerships, auto repair garages, and the automotive sector hub.

A car dealership brings together activities of fundamentally different natures under one roof. New vehicles (VN) is a low-margin-per-unit retail business, heavily dependent on manufacturer bonuses (RFA). Used vehicles (VO) is a trading activity whose profitability depends on trade-in policy, days in stock, and a specific VAT regime. The mechanical workshop is a service production activity whose primary lever is technician productivity. The parts and accessories department is a retail operation with its own stock rotation and shrinkage dynamics. Bodywork is a semi-craft activity driven by insurance flows, repair lead times, and dedicated labour management.

Rolling all these activities into a single profit and loss statement means mixing revenue streams, cost structures, and management levers that have very little in common. Departmentalisation creates as many mini P&Ls as there are activities.

For independent garages, the logic is the same even if the departments are fewer: separating workshop labour, parts, bodywork, and potentially vehicle sales is the foundation of useful management.

The Allocation Principle#

The principle is straightforward: every item of revenue and every cost must be attributed to the department that generated it. In practice, some allocations are direct; others require pre-defined allocation keys.

Directly attributable revenue:

• New vehicle sales → VN department
• Used vehicle sales → VO department
• Workshop labour invoiced → workshop department
• Counter parts sales → parts department
• Bodywork labour and paint → bodywork department
• Manufacturer bonuses (RFA) → VN department as a priority, split if multi-criteria

Directly attributable costs:

• Technician salaries and social charges → workshop
• VN and VO sales staff → respective departments
• Bodywork and paint technician costs → bodywork
• Parts and stores staff → parts department
• Cost of vehicles traded in → VO

Costs allocated by key:

• Premises rent and charges → floor area per department
• Energy → estimated consumption or floor area
• Insurance → revenue or headcount
• Shared functions (management, accounting, reception) → pre-defined key

The quality of management accounting depends on the consistency of these keys and their stability over time. Changing keys between periods makes year-on-year comparison meaningless.

Internal Recharges: The Parts-to-Workshop Flow#

The parts department sells both over the counter (external customers) and internally to the workshop and bodywork department. If this distinction is not isolated, the parts department margin is overstated and the workshop margin is understated. Internal recharges solve this: the workshop 'buys' its parts from the stores department at a formalised internal price — catalogue price, catalogue price less an internal discount, or purchase price plus a coefficient.

This internal price must be stable, documented, and applied systematically. It does not represent a real cash flow but an analytical entry that assigns each department its true consumption and its true margin.

New Vehicles#

• Unit gross margin: selling price minus manufacturer invoice cost, before RFA
• Net VN margin: after integrating manufacturer bonuses and commercialisation costs (preparation, sales staff bonuses, financing)
• Average VN stock days: the longer a new vehicle sits in stock, the more the financing cost erodes the real margin
• Finance penetration rate: manufacturer KPI, but also a lever for margin through finance commissions

On new vehicles, the pre-bonus margin is often structurally thin. The risk is becoming dependent on manufacturer bonuses that can be revised, reduced, or tied to demanding qualitative targets. Bonuses not yet invoiced at year-end should be accrued as income receivable if acquisition is certain or highly probable.

Used Vehicles#

• Gross VO margin: selling price minus trade-in price (or purchase price) minus reconditioning costs
• Days in stock: used vehicles depreciate quickly; a VO immobilised beyond 60 to 90 days creates downward pressure on resale margin
• Average reconditioning cost: to monitor if the bodywork department carries out work on VO inventory
• VAT regime awareness: VO purchased from private individuals or non-VAT-deductible professionals are subject to VAT on the margin (art. 297 A of the French General Tax Code) — VAT applies to the difference between selling price and purchase price, and does not appear separately on the invoice. VO purchased with recoverable VAT fall under the standard regime. This distinction is structurally important for both accounting and tax purposes.

For intra-EU transactions, the quitus fiscal issued by the local tax office (SIE) certifies VAT regularisation for new vehicles acquired from another EU member state and is required for registration.

Mechanical Workshop#

This is the department where management is most technical.

• Productive hours sold: hours actually invoiced to clients during the period
• Occupation rate: hours sold divided by technician presence hours, excluding breaks, training, and loan vehicles
• Average hourly rate sold: workshop labour revenue divided by hours sold
• Productivity per technician: identifies gaps between profiles and supports scheduling decisions
• Workshop margin: labour revenue minus direct workshop costs (salaries and charges) minus internal parts consumed

The key tension is between the posted hourly rate and the rate actually absorbed. A technician not assigned to a repair order generates cost without generating revenue. A well-run workshop tracks assignments in real time, ideally through the dealer management system (DMS).

Parts and Accessories#

• Parts gross margin rate: on counter sales and internal sales combined
• Stock rotation: frequency of active stock replenishment; dormant stock ties up working capital without generating margin
• Service rate: proportion of references immediately available in stock versus ordered with lead time
• Shrinkage and obsolescence: parts that have gone off-catalogue or deteriorated and need to be written down

Bodywork#

• Bodywork margin: revenue (insurers plus direct clients) minus direct costs (labour, paint, internal parts)
• Average repair lead time: indicator of workshop fluidity and insurer agreements
• Quote completion rate: consistency between what is quoted and what is invoiced
• Capacity versus load: available hours of bodywork and paint technicians versus work in progress

Bodywork operates with insurers and loss adjusters who impose reference tariffs. Real margin depends on the ability to negotiate labour time allowances, control paint costs, and limit rework.

In the dealership files we work with, the overall result rarely reflects the real internal balance. The most frequent situations:

The workshop subsidises new vehicle sales. The dealership achieves a positive result thanks to workshop productivity, while the VN department operates at zero or negative margin before manufacturer bonuses. If the manufacturer revises its targets or scales, the overall balance tips.

Used vehicles absorb cash invisibly. Trade-ins are made at market prices, reconditioning costs are pooled at a global level, and days in stock lengthen. VO margin looks acceptable but conceals slow rotation and inflated working capital.

The parts department funds the workshop without knowing it. Without formalised internal recharges, parts consumed by the workshop do not transit through an internal price; the parts margin is overstated and the workshop appears more profitable than it is.

None of these imbalances are detectable unless management accounting is correctly populated and read regularly — ideally monthly — rather than only at the annual accounts.

The vast majority of automotive sector software (DMS) natively integrates an analytical structure by department. The challenge is not technical but organisational.

Key points to watch:

• Ensure every repair order, every sale, and every purchase is assigned to a department at the point of entry, not at month end
• Define and document allocation keys for shared costs
• Formalise internal recharge prices and review them at the start of each financial year
• Reconcile management accounting with general accounting regularly (totals must match)
• Produce a monthly department-level report, not only an annual one

On the payroll side, the sector falls under the collective agreement for automotive services (IDCC 1090), signed 15 January 1981, which covers all roles — mechanics, bodywork and paint technicians, service advisors, parts staff, VN/VO sales staff, workshop managers, apprentices, and administrative functions. The sector's social protection body is IRP AUTO. Accurate payroll structured by department also supports analytical clarity.

Used vehicle dealers are also required to maintain a livre de police (register of secondhand vehicles), recording purchases, sales, party identities, and vehicle descriptions — a separate legal obligation that complements the analytical traceability of VO operations.

• Define the analytical departments to be tracked (VN, VO, workshop, parts, bodywork, other)
• Configure analytical codes in the DMS and accounting software
• Document allocation keys for shared costs
• Formalise internal recharge prices for parts to workshop and parts to bodywork
• Train administrative teams on systematic allocation at the point of entry
• Produce a first complete analytical report and validate it with your accountant
• Integrate the analytical report into the monthly management dashboard
• Review keys and internal prices at the start of each financial year

This article reflects the position as of 4 June 2026. It is intended for information purposes only and does not replace a review of your specific situation, your documents, and applicable law. An accountant with automotive sector expertise can configure and maintain this analytical framework in your context.

Principal sources: Plan comptable général (PCG, ANC), manufacturer reporting standards, French General Tax Code art. 297 A (VAT on margin for used vehicles), Convention collective nationale des services de l'automobile IDCC 1090 of 15 January 1981.