Index
Why the purchase price is not the real cost
Expenses that actually form part of the real cost
Expenses that do not form part of the vehicle's real cost
How to calculate the real cost with a complete example
Which expenses reduce the REBU margin and which are only deductible as business expenses
How to record expenses correctly so that the calculation is reliable
Dealcar and the control of the real cost per vehicle
Frequently asked questions
Why the purchase price is not the real cost
A dealership buys a car for €11,500 and sells it for €15,200. The apparent margin is €3,700. But before reaching the final buyer, that car has accumulated €380 in transport, €620 in workshop repairs, €95 in agency fees, €48 for the MOT (ITV), and €67 in financing interest during the 32 days it was in stock. The real cost of the vehicle is €12,710. The real net margin is €2,490, which is 33% less than it seemed.
That difference is not small. Multiplied by 15 or 20 transactions a month, it can represent several thousand euros of overestimated profit that the owner believes they have, but which doesn't actually exist. Making stock purchase decisions based on the apparent margin rather than the real margin leads to paying too much for vehicles that later do not generate the expected profit.
See also the hidden costs of a dealership that distort the margin.
Expenses that actually form part of the real cost
Transport from the place of purchase to the dealership is the first direct expense. If the car is collected from a private individual's home by a carrier, that cost goes to the vehicle's file. If the owner brings it themselves in their van, the fuel cost and time are also attributable to that transaction, even if there is no invoice from a third party. For imported cars, transport from the country of origin can be the most significant direct expense: between €200 and €550 depending on the origin.
Mechanical and bodywork repairs are the second direct expense. Any workshop work required to get the car into sellable condition counts towards the real cost: brake changes, tyres, replacement of faulty parts, body damage repair. Each workshop invoice featuring the vehicle reference is added to the entry cost.
Ownership transfer processing (gestoría) into the dealership's name (when buying from a private individual) or into the final customer's name costs between €60 and €150 depending on the procedure and the agency. It is a small expense per transaction, but it is constant and must be included in the file.
The MOT (ITV), if the vehicle's technical inspection has expired, is a cost that must be recorded in the file. It is not an overhead of the business: it is a specific cost for that vehicle so that it can be legally driven.
Financing interest if the car is financed with a stock finance line or through DealFlex. For a €12,000 vehicle with 7% annual financing that takes 45 days to sell, the interest is: 12,000 × 0.07 / 365 × 45 = €103.56. It does not appear directly on any invoice associated with the vehicle, but it is a real cost that forms part of the margin of that transaction.
Read also what the floor plan is and how to calculate its cost per vehicle.
Preparation for advertising if contracted externally: professional vehicle photography, deep cleaning before photos, interior detailing. If it has an invoice with the vehicle reference, it goes in the file.
Expenses that do not form part of the vehicle's real cost
There are business expenses that affect the dealership's profitability but are not attributable to a specific vehicle, and therefore do not form part of the real cost of each transaction.
Premises rent, listing portal fees, management software, staff payroll, business insurance, and utility bills are overheads that are spread across all transactions of the period but cannot be attributed to a specific car. They are tax-deductible as business expenses, but they do not enter into the calculation of the margin per vehicle.
The commercial warranty offered to the buyer also does not form part of the real cost of the vehicle from a REBU point of view. If invoiced separately as an additional service, it is taxed at the general VAT rate. If it is included in the car's price, it is part of the sale price, not the cost.
Light cosmetic preparation (basic interior cleaning, degreasing) falls into a grey area: if done using in-house resources without an external invoice, there is no direct cost to record. If contracted externally and invoiced, it can be included in the file, although its deductibility from the REBU margin is not explicitly regulated.
Read our article "Deductible expenses for second-hand car dealerships".
How to calculate the real cost with a complete example
Vehicle: Seat Leon 2019, 78,000 km, purchased from a private individual.
Concept | Amount |
|---|---|
Purchase price from private seller | 10,800 € |
Transport (home collection) | 210 € |
Workshop (brakes + filters + minor repairs) | 480 € |
MOT (expired) | 52 € |
Agency fees (transfer into dealership's name) | 85 € |
Financing interest (38 days at 7%) | 78.93 € |
Total real cost | 11,705.93 € |
If the vehicle is sold for €14,500, the apparent gross margin (sale price minus purchase price) is €3,700. The real net margin (sale price minus total real cost) is €2,794.
The €906 difference between the two calculations is not small. If the dealership sets the minimum selling price based on the apparent margin, they may be selling below their real profitability threshold without realising it.
For the REBU margin calculation on the 303 tax form, the taxable base is the sale price minus the purchase price minus deductible expenses (transport and repairs, in this case 210 + 480 = €690). REBU taxable base: 14,500 − 10,800 − 690 = €3,010. VAT to settle: 3,010 × 21 / 121 = €522.56.
Check what data must be recorded in the REBU registry book per transaction.
Which expenses reduce the REBU margin and which are only deductible as business expenses
Not all expenses in the real cost reduce the taxable base for the REBU. The distinction is important for the 303 form.
Check the complete guide on which expenses reduce the REBU margin and how to calculate it.
The expenses that reduce the REBU margin are vehicle transport and repairs (mechanical and bodywork). Both must be documented with an invoice showing the vehicle reference.
Expenses that do not reduce the REBU margin but are deductible as business expenses include the MOT, transfer agency fees, and financing interest. These costs form part of the real cost of the transaction and are deducted in Personal Income Tax (IRPF) or Corporate Tax as business expenses, but they do not go into box 25 of the 303 form.
Confusing the two types leads to two opposite mistakes: including expenses in the REBU margin that do not belong (MOT, agency fees) and forgetting to deduct those that do not belong in the REBU margin as business expenses (financing interest). Both mistakes distort the tax return.
How to record expenses correctly so that the calculation is reliable
The correct time to record each expense is when it occurs, not at the end of the month. If the workshop invoice arrives today, it should be entered today in the vehicle file with the license plate or VIN reference. If you wait until the end of the quarter to do this recording, some invoices will likely be missing or the vehicle reference will no longer be clear.
Each direct expense invoice must include the reference of the vehicle it corresponds to: license plate or VIN. Without this reference, the administrator cannot associate the expense with the correct file and may classify it as a general business expense, distorting the margin per transaction.
For expenses that do not have an invoice (own fuel costs for a transfer, a small repair paid in cash with a receipt), keep whatever proof is available and note down the amount in the file with a description of the concept.
Read also how to prepare the accounting documentation for each vehicle.
Dealcar and the control of the real cost per vehicle
Dealcar allows you to record all components of each vehicle's real cost in its file right from the moment of purchase: entry price, transport, repairs, agency fees, and MOT. The real net margin is calculated automatically at the close of the sale, integrating all those costs without additional manual work.
See also the electronic invoicing page for Dealcar dealerships.
The system automatically distinguishes between expenses that reduce the REBU margin (transport and repairs) and those that are deductible as business expenses, so that the quarter's totals sent to the administrator are already correctly classified.
You can see how vehicle cost control works at dealcar.io/software-concesionario or request a demo at dealcar.io.
Frequently asked questions
Is there a limit on the transport amount that can be included in the real cost?
There is no legal limit, but the amount must be reasonable and documented with an invoice. A €800 transport cost for a €4,000 car might draw attention in an inspection and require additional justification, although it is perfectly valid if it reflects the real cost of the transfer.
Do financing interests reduce the REBU margin?
No. Interest from a stock finance line or DealFlex is a business financial cost that is deducted in Personal Income Tax (IRPF) or Corporate Tax, but not in the REBU margin calculation. They do form part of the real cost of the transaction to calculate the business's net margin, but not of the taxable base of form 303.
What happens if the car is sold at a loss and the margin is negative?
A negative margin under the REBU has a taxable base of zero: there is no VAT to settle for that transaction. The negative margin cannot be offset against positive margins from other transactions in the same quarter: each REBU transaction is handled separately. The loss is deductible as a business expense in Personal Income Tax (IRPF) or Corporate Tax.
Does cosmetic preparation (washing, polishing) count towards the real cost?
If it has an invoice from a third party with the vehicle reference, yes, it counts towards the real cost of the transaction. Its deductibility specifically from the REBU margin is not explicitly regulated, so the most prudent approach is to include it in the real cost for calculating the net margin but not in the REBU taxable base. Consult your tax advisor if the amount is significant.
