Mobility Budget: The 10 Questions Your Employees Will Ask You (and the Answers the Law Doesn’t Always Provide Clearly)

Belgium’s mobility budget becomes mandatory in 2027 for companies with 50+ employees, and in 2028 for those with 15-50 employees. The theory is well known. The practice is much less so.

These ten questions come directly from the field: sector webinars, client workshops, and conversations with HR managers and fleet managers. These aren’t academic questions. They’re the questions that block decisions.

1. Is My Company Really Obligated?

It depends on three criteria.

Company Size : The obligation applies to companies with 50+ employees (2027) and 15-50 employees (2028). Companies with fewer than 15 employees are not affected.

Calculating Number of Employees : You take the average of the 4 quarters before the obligation applies. For an obligation in Q1 2027, this means Q4-2025, Q1-2026, Q2-2026, and Q3-2026. It’s the average, not the peak.

Prerequisite Condition : The employer must have offered company cars continuously for at least 36 months before introducing the mobility budget. Without company cars in the package, there’s no possibility of offering a mobility budget (until at least one car has been offered for 36 months).

Who Is an “Employee”? : All employees: salaried employees, management, and blue-collar workers. All categories of personnel are counted.

2. Can We Implement It Now Without Waiting Until 2027?

Yes, and it’s even recommended. Take the time to do it before and do it well. It will be mandatory and unlikely to change, so why wait? There are no penalties for getting ahead of the deadline.

The advantage of starting early: You have time to test, adjust, and fix problems before the obligation takes effect. Companies that wait until the last moment often end up with minimal implementations that satisfy no one.

3. If an Employee Refuses the Mobility Budget, Is That Final?

No, the refusal is not final. Actually, I should say: there is no refusal. The mobility budget is mandatory for employers but not for employees, who are free to keep only their company car outside the mobility budget. An employee who declines the mobility budget at any point can change their mind later. The employer must maintain the possibility to choose the mobility budget on a permanent basis (or at least at the end of a leasing contract), not only during an annual enrollment window.

In Practice : Most refusals come from lack of information or poor presentation of options. When concrete alternatives are explained (amounts, pillar 2 possibilities, fiscal impact of pillar 3), adoption rates increase significantly. From experience, when employees who are entitled to a company car learn that by choosing a smaller or less premium vehicle they can have budget to spend on mobility or less taxed compensation than a bonus, many reconsider their actual needs. Others, who love cars, continue to enjoy their choice. And that’s perfectly fine.

4. Do Taxis and Rental Cars Need to Be Electric?

This is the question that creates the most confusion. The law amendment in December 2023 (effective January 1, 2026) created a multi-level system within pillar 2. Article 3, §1, 8°, d) distinguishes three subcategories in the “shared mobility solutions” category, and point 11° of Article 25 clarifies that only the motorized vehicles referred to in “the first and third subcategories” must have zero emissions.

Here’s what this means in practice:

Shared Vehicles (Cambio, Poppy, etc.): Yes, zero emissions mandatory since January 1, 2026. This is the “first subcategory” of Article 3, §1, 8°, d).

Ride-Sharing Services with Driver (Uber, Bolt, etc.): Yes, zero emissions mandatory. This is the “third subcategory,” explicitly covered by the requirement.

Taxis : This is the “second subcategory” — and it is NOT included in the reference to “first and third subcategories” in point 11°. According to this reading of the law, taxis are not subject to the zero-emission requirement. However, some advisors interpret the text differently, and in practice, based on a taxi receipt alone, it is impossible to determine the vehicle’s motorization. This gray area is not (yet) being enforced.

Standard Rental Cars Without Driver (Hertz, Avis, vacation rentals): This category appears in a separate provision (“rental of vehicles without driver, for a maximum of 30 calendar days per year”) and is not covered by the zero-emission requirement.

Recommendation : Document your internal policy on these points. The legal text leaves room for interpretation, particularly for taxis. In case of an audit, your approach’s consistency and good faith will be evaluated. We recommend monitoring administrative guidance updates on this topic.

5. Is Pillar 2 100% Tax Deductible?

Pillar 2 expenses (public transport, bicycles, e-scooters, carpooling, etc.) are fully tax-deductible for the employer. This is one of the structural advantages of the mobility budget compared to a traditional company car, especially in the coming years as company car tax deductibility decreases.

For the employee, amounts spent in pillar 2 are exempt from social security contributions and income tax. It’s net, just like a company car. Pillar 3 is taxed at a flat rate of 38.07%, and the vehicle in pillar 1 is subject to a benefit in kind (BIK) — in French, avantage de toute nature (ATN) — like any company vehicle.

6. Does Pillar 1 Follow Company Car Tax Rules?

Yes. The pillar 1 vehicle is subject to the same tax rules as a traditional company car. Specifically, since January 1, 2026:

The pillar 1 vehicle must be 100% electric (zero emissions)
Tax deductibility is 100% in 2026 (the last year at this rate)
It will drop to 95% in 2027, then decrease progressively

The CO2 solidarity contribution (paid to the NSSO — National Social Security Office, also known as ONSS) still applies to the pillar 1 vehicle, but it is obviously much lower for an electric vehicle than for a gas-powered one (especially since this contribution was quadrupled in 2026 for non-electric vehicles).

7. How Do You Handle Business Travel?

This is a matter of consistency with your existing policy.

Basic Rule : If business travel was previously covered by the company car (fuel/leasing/insurance), then it logically falls under the mobility budget. The mobility budget replaces the car in its entirety, including its professional use. An employee who takes a business trip (within Belgium) by train or using a shared vehicle must pay for it with their mobility budget.

Exception : If the company had a separate system for reimbursing business travel expenses (per-kilometer allowance, separate fuel card), this system can be maintained alongside the mobility budget.

Recommendation : Clarify this point BEFORE implementation. This is the first source of confusion among workers transitioning to a mobility budget.

8. What About Public Sector Organizations, Schools, and Nonprofits?

The question comes up regularly: “My organization doesn’t offer company cars. Can we still offer a mobility budget?”

Short Answer : No. The requirement for 36 months of company car offerings is a sine qua non condition. Without a history of company cars, a mobility budget is not available.

Alternative : These organizations can offer mobility benefits through other mechanisms (public transport subscriptions, bike allowances, corporate mobility plans). It’s not a “mobility budget” in the legal sense, but the practical effect can be similar.

9. How Do You Ensure the Budget Doesn’t Explode?

This is THE question CFOs ask. The answer rests on three mechanisms.

The Legal Cap : The mobility budget is capped at a maximum of 1/5 (20%) of the employee’s annual gross salary, with an absolute maximum of 17.244 €/year and a minimum of 3.233 €/year (2026 amounts). The current company car’s total cost of ownership (TCO) serves as the calculation basis.

Indexing : The mobility budget is not automatically indexed to changes in your company car list, though we recommend doing so for fairness. If you increase your company car list’s TCO from one year to the next, you are not required to increase existing mobility budgets. New participants can have the new TCO applied to them, but existing budgets remain stable (unless your internal policy says otherwise).

Pillar 3 as a Buffer : Any amount not spent in pillars 1 and 2 is paid out as cash (pillar 3), subject to a special social security contribution of 38.07%. For the employer, this cost is predictable and lower than a company car’s TCO.

No Surprises : Unlike fuel budgets for vehicles or leasing costs that can vary based on kilometers driven and charging expenses, the mobility budget is fixed at the start of the year and won’t blow up unexpectedly.

In Numbers : An average mobility budget of 10.000 €/year costs the employer 10.000 € . Compare this to the average TCO of a company car: 8.000-15.000 €/year depending on the segment.

10. Can an Employee Keep Their Current EV Lease and Switch to a Mobility Budget?

Yes, but with a specific procedure.

Administratively, the employer must remove the company car from the employee’s DmfA (multi-functional declaration) and then reassign it the next day as a pillar 1 vehicle within the mobility budget. It’s a technical process, but it’s necessary for the mobility budget’s tax framework to apply correctly.

In Practice : The transition is possible at any time, not just at the end of a leasing contract. However, the employer can reasonably request that the transition coincide with a logical administrative time point (the start of a quarter, for example).

The Common Thread in These 10 Questions

None of these questions has an obvious answer. That’s precisely why only 4.51% of Belgian companies currently offer a mobility budget: the legal framework exists, but translating it into operational reality requires preparation work that few companies have the time or expertise to do alone.

The 2027 obligation won’t reduce this complexity. It will only add urgency.

Workshop “Mobility Budget: From Theory to Practice”

Want to go beyond theory? Next Mobility is organising practical workshops in May and June 2026 to give you all the tools you need to implement the mobility budget in your company.

In half a day or a full day, you leave with a customisable Mobility Policy, a communication kit for your employees, a 6-phase implementation checklist, and a decision grid for tooling and for professional travel. Maximum 8 participants per session to ensure interactivity.

Upcoming sessions (to be confirmed): Tuesday 12 May, Thursday 4 June and Wednesday 17 June 2026.

Interested? Contact me to reserve your spot: info@nextmobility.be

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