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Registration tax 2026-2027: Brussels, Wallonia or Flanders, which taxes your car the most?
Brussels registration tax, the Walloon CO2 and mass formula, the Flemish BIV: the three regimes compared using 2026-2027 rates, with worked examples for petrol, diesel, SUVs and EVs.
Registration tax (TMC), known as BIV in Flanders, is paid only once, when the vehicle is registered. But depending on whether you live in Brussels, Wallonia or Flanders, the same car can cost a few dozen euros or several thousand. Each region has its own logic: power in Brussels, power combined with CO2 and mass in Wallonia, CO2 in Flanders. Here is the comparison, using the rates in force from 1 July 2026 to 30 June 2027.
Brussels: power and nothing else#
In Brussels, registration tax depends solely on engine power. It can be read in two ways, in fiscal horsepower (CV) and in kilowatts (kW), and it is whichever reading gives the higher amount that applies. The rates are indexed every 1 July:
| Fiscal horsepower | or engine power | Registration tax 2026-2027 |
|---|---|---|
| 8 CV or less | 70 kW or less | €78.88 |
| 9 and 10 CV | 71 to 85 kW | €157.76 |
| 11 CV | 86 to 100 kW | €634.89 |
| 12 to 14 CV | 101 to 110 kW | €1,112.01 |
| 15 CV | 111 to 120 kW | €1,589.14 |
| 16 and 17 CV | 121 to 155 kW | €3,178.28 |
| Over 17 CV | Over 155 kW | €6,357.85 |
The kW reading often changes everything: a car rated at 8 CV but with 85 kW pays €157.76, not €78.88. Above 155 kW, you pay the maximum, whatever the engine capacity. CO2 emissions have no impact, and an electric car pays the minimum tax, €78.88.
Two caveats. A car registered by a leasing company pays the non-indexed rates (from €61.50 to €4,957). And Brussels has announced a reform for the second half of 2027, with a weight-related coefficient in the registration tax: we cover it in detail in our article on the Brussels reform.
Wallonia: power, CO2 and mass in a single formula#
Since 1 July 2025, Wallonia no longer has an eco-malus. Registration tax follows a single formula:
Registration tax = base amount × (CO2 ÷ 136) × (maximum authorised mass ÷ 1,838 kg) × energy coefficient
- The base amount depends on power (the same CV and kW bands as in Brussels): from €64.01 (70 kW or less) to €5,159.25 (over 155 kW) for 2026-2027.
- CO2 is compared with 136 g/km (WLTP): a car that emits less pays less than the base amount, a car that emits more pays more.
- The maximum authorised mass (box F1 on the registration certificate) is compared with 1,838 kg: heavier vehicles pay more.
- The energy coefficient is 1 for petrol and diesel and 0.8 for a plug-in hybrid. For an electric car, CO2 is not taken into account and the coefficient depends on power: 0.01 up to 120 kW, 0.10 up to 155 kW, 0.18 up to 249 kW, 0.26 above that.
- Walloon registration tax is capped at €9,000 and does not fall below €50.
The upshot: a small electric car pays the €50 minimum, but a powerful electric car is no longer spared. A Tesla Model Y RWD (188 kW) pays €928.67. Conversely, a big, heavy SUV quickly hits the cap: with its actual maximum mass of around 2,950 kg, a BMW X5 40d pays the full €9,000.
Flanders: the BIV, a CO2-based tax#
The Flemish BIV ignores power. It follows a formula laid down in the Vlaamse Codex Fiscaliteit, which combines CO2, the Euro standard, fuel and age. For a car first registered in 2021 or later:
BIV = ((CO2 × q ÷ 246)⁶ × 4,500 + air component) × age correction
- CO2 (WLTP) is multiplied by a factor q that rises every year: 1.245 in 2026. Because it is raised to the power of 6, the tax climbs very quickly with emissions: a CO2 component of €204 at 118 g/km, €1,269 at 160 g/km, €3,031 at 185 g/km.
- The air component depends on the Euro standard and the fuel. Under Euro 6, it is €28.54 for a petrol car or a hybrid, but €628.89 for a diesel. The older the standard, the higher it goes.
- The amount does not fall below €58.16 and does not exceed €14,539.31 (amounts indexed on 1 July 2026).
- Electric cars: the end of the exemption. An electric car registered since 1 January 2026 pays a flat €61.50. Those registered earlier remain exempt.
As in Brussels, a car registered by a leasing company escapes the regional rates: it pays the non-indexed federal rates, based on power.
Five cars, three bills#
Let us apply the three regimes to five models from the catalogue, new, registered by a private individual. In Wallonia, the maximum authorised mass is set at the reference value of 1,838 kg (neutral component), unless stated otherwise.
| Vehicle | Brussels | Wallonia | Flanders |
|---|---|---|---|
| VW Golf eTSI — petrol, 8 CV, 85 kW, 118 g/km | €157.76 | €111.08 | €232.67 |
| Audi Q3 TDI 110 — diesel, 11 CV, 110 kW, 142 g/km | €1,112.01 | €942.18 | €1,248.83 |
| BMW X5 40d — diesel, 15 CV, 230 kW, 185 g/km | €6,357.85 | €7,018.10 (€9,000 with its actual mass) | €3,660.34 |
| Renault 5 electric — 90 kW | €78.88 | €50.00 | €61.50 |
| Tesla Model Y RWD — electric, 188 kW | €78.88 | €928.67 | €61.50 |
How to read it: the economical Golf is lightly taxed everywhere, and it pays least in Wallonia because its CO2 is below 136 g/km. The compact diesel pays more in Flanders than elsewhere: under Euro 6, a diesel's air component costs €600 more than a petrol car's. The big, powerful diesel remains taxed far more heavily in Brussels and Wallonia, where power counts, even if its 185 g/km pushes the Flemish BIV above €3,600. For electric cars, Flanders and Brussels apply a small flat amount, while Wallonia taxes powerful models: the Tesla Model Y pays close to €930 there.
Used cars: a reduction based on age#
For a used vehicle, registration tax is reduced according to its age at registration. In Brussels and Wallonia, the reduction applies to the base amount (in Wallonia, before the CO2 and mass formula):
| Vehicle age | Share of the new-car amount |
|---|---|
| Under 1 year | 100% |
| 1 year | 90% |
| 2 years | 80% |
| 3 years | 70% |
| 4 years | 60% |
| 5 years | 55% |
| 6 years | 50% |
| 8 years | 40% |
| 10 years | 30% |
| 14 years | 10% |
| 15 years and over | Minimum amount |
The amount never falls below the minimum in the rates. Example: the Audi Q3 TDI bought used at 3 years old pays €778.41 in Brussels and €659.53 in Wallonia. The Flemish BIV follows its own age correction: 90% of the new-car amount at 1 year, then 10 points less each year, down to 10% beyond 9 years. The same 3-year-old Q3 pays €874.18 there, or 70% of the new-car amount.
Not to be confused with road tax#
Registration tax is a one-off cost, paid on registration. It comes on top of the annual road tax. In Brussels and Wallonia, road tax follows a scale based on fiscal horsepower, valid from 1 July 2026 to 30 June 2027:
| Fiscal horsepower | Road tax per year |
|---|---|
| 4 CV or less, and electric cars | €107.18 |
| 5 CV | €134.11 |
| 6 CV | €193.91 |
| 8 CV | €313.24 |
| 10 CV | €432.30 |
| 11 CV | €561.00 |
| 15 CV | €1,075.54 |
| 20 CV | €2,741.77 |
| Over 20 CV | +€149.56 per CV |
In Flanders, an electric car registered since 2026 pays €69.72 to €87.24 a year depending on its fiscal horsepower. Over four or five years of ownership, this recurring tax often weighs more than the registration tax itself: a BMW X5 40d pays €1,075.54 a year in Brussels or Wallonia. Both costs deserve to be calculated together.
What changes in 2027#
- 1 July 2027: annual indexation of the Brussels and Walloon rates (registration tax and road tax). The new amounts have not yet been published.
- May 2027: the announced arrival of the road vignette, between €90 and €125 a year.
- Second half of 2027, in Brussels: road tax exemption for electric cars and cars of 5 CV or less, a reduction for others (excluding leased cars), and a weight-related coefficient in the registration tax. These measures have been announced but not yet adopted: AutoCalcul will apply them as soon as the texts are published.
Key takeaways#
Registration tax is one of the few items in the total cost of ownership (TCO) that you can optimise without changing car:
- in Brussels, modest power, in CV as well as in kW, brings the bill right down;
- in Wallonia, low CO2 and a light mass count as much as power, and a powerful electric car is no longer spared;
- in Flanders, CO2 counts above all, diesel pays a heavier air component, and electric cars pay a small flat amount.
The rates for all three regions are built into the calculation engine and checked against official sources. Electric cars also win on deductibility and, for the self-employed, on VAT. Before you buy, especially a powerful vehicle or a nearly new used car, calculate the registration tax for your region: the difference can run to several thousand euros.
Tax rules change — check the legislation in force.
Frequently asked questions
- Which region charges the least registration tax on an electric car?
- Since 1 January 2026, a new electric car pays a flat €61.50 BIV in Flanders. In Brussels, it pays the minimum registration tax of €78.88. In Wallonia, the tax depends on power: €50 for an electric car of 120 kW or less, but €928.67 for a 188 kW Tesla Model Y RWD.
- Does the Walloon eco-malus still exist?
- No. For registrations since 1 July 2025, Wallonia has replaced the eco-malus with a single formula that multiplies a power-based base amount by CO2, maximum authorised mass and an energy coefficient. CO2 is built directly into the registration tax calculation.
- Is registration tax reduced for a used car?
- Yes. In Brussels and Wallonia, the amount falls with the vehicle's age: 10% less for each year of age, after which the reduction slows down and the amount reaches the minimum at 15 years. A 3-year-old car pays 70% of the new-car amount. In Flanders, the BIV follows its own age correction: 90% of the new-car amount at 1 year, then 10 points less each year, down to 10% beyond 9 years.
- Will registration tax amounts change in 2027?
- The current Brussels and Walloon rates apply until 30 June 2027; they will be indexed on 1 July 2027. Brussels has also announced a weight-related coefficient in its registration tax from the second half of 2027, but the rates have not been published yet.