The mobility budget is a Belgian mechanism that allows employees entitled to a company car to convert all or part of that benefit into a budget for more sustainable travel alternatives.

Introduced by the law of 17 March 2019, the system was until now entirely voluntary. That is no longer the case: the De Wever government has made it mandatory for employers who provide company cars, with a phased implementation starting in 2026.

For HR teams and fleet managers, understanding this framework — and preparing for it — has become a priority. This guide takes stock of the current rules, the 2026 changes, and what needs to be done right now.

The mobility budget allows an employee with entitlement to a company car to give it up — in full or in part — in exchange for a budget equivalent to the Total Cost of Ownership (TCO) of that car.

This budget can be used to fund alternative mobility solutions, spread across three distinct pillars, each with its own tax treatment.

Since the budget is calculated on the TCO of the surrendered car, the employer bears no additional cost: the mobility budget is a substitution mechanism, not an extra benefit.

🚗 Pillar 1 — Eco-Friendly Company Car

The employee may choose a cheaper, more environmentally friendly company car. Any remaining budget automatically flows into Pillars 2 and/or 3.

🚲 Pillar 2 — Sustainable Mobility Solutions

The most fiscally advantageous pillar. Expenses are exempt from personal income tax and social security contributions. Eligible items include:

• Bicycles (standard, electric, cargo) and accessories
• Electric mopeds, motorcycles and three-wheelers (zero-emission only)
• Public transport subscriptions (train, tram, bus, metro) — including for household members
• Shared mobility: car-sharing, scooter-sharing, taxis — zero-emission only from 2026
• Housing costs if the employee lives within 5 km of the workplace

💶 Pillar 3 — Cash Payout

Any unspent balance at year-end is paid out in cash. This payment is subject to a special social security contribution of 38.07% (borne by the employee), but is exempt from personal income tax and employer social security contributions.

On the employer side: the obligation (or option) to offer the mobility budget applies to employers who have provided one or more company cars for a cumulative period of more than 36 months, whether consecutive or not.

On the employee side: the employee must currently have a company car or be entitled to one under the company's car policy. They must also have at least 3 months' seniority and have benefited from (or been entitled to) a car for at least 3 months.

Important note: an employee who gives up their company car may not request a new one for at least 3 years, except in the event of a significant change in job function.

The mobility budget amount corresponds to the TCO of the surrendered company car. The law sets annual floor and ceiling amounts, indexed each year.

If the TCO falls below the floor, the employee still receives the minimum. If it exceeds the ceiling, the budget is capped at the legal maximum.

2026 is a turning point for the mobility budget. Here are the key changes HR teams need to know:

The De Wever coalition agreement includes the mandatory rollout of the mobility budget as a key pillar of its mobility and tax reform agenda. However, the legislative path has been more complex than initially anticipated.

These deadlines only apply to employers who have provided a company car for more than 36 cumulative months.

One of the key strengths of the mobility budget is its highly favourable fiscal architecture, particularly for Pillar 2 expenses:

For employers: no employer social security contributions are due on any of the three pillars, provided the budget strictly equals the TCO of the surrendered vehicle. This is a significant advantage over any other alternative remuneration mechanism.

Whether your company is already above or below the mandatory thresholds, preparing early is strongly advisable. Here is a practical action plan:

• Audit your fleet: identify how long company cars have been provided and which employees are eligible for the mobility budget.
• Review your car policy: check whether it mentions (or excludes) the mobility budget and update it accordingly.
• Electrify Pillar 1: make sure your leasing catalogue only includes 100% electric vehicles for Pillar 1.
• Inform your employees: every eligible employee must receive clear, unbiased information about the system — their potential budget amount, available options, and how to exercise their choice.
• Set up an administrative process: define how you will calculate TCO, validate Pillar 2 expenses, and process the annual Pillar 3 cash payout.
• Monitor legislation: track the Belgian Official Gazette for publication of the mandatory mobility budget law, expected between April and June 2026.
• Consider a mobility platform: tools like Mbrella, Skipr or similar solutions automate employee choices, expense validation and reporting.

Belgium's mobility budget is no longer a niche HR benefit — it is becoming a core component of every Belgian employer's compensation and mobility strategy.

The 2026 reforms significantly tighten environmental requirements (electric-only for Pillar 1, zero-emission for shared mobility in Pillar 2), while the pending mandatory legislation sends a clear political signal: all significant Belgian employers providing company cars will soon be legally required to offer this alternative to their employees.

For HR and fleet managers, the window to act proactively is open now. Companies that build a structured, compliant and well-communicated mobility budget offering ahead of the legal deadlines will be better positioned to attract talent, reduce their carbon footprint, and fully benefit from the system's generous fiscal advantages.