Keeping a fair mobility budget policy for part-time employees

Mobility budgets are supposed to make life easier (and better?). More freedom for employees, fewer company cars on the road, and a cleaner way to talk about mobility in a world where commuting doesn’t look the same for everyone anymore. With the mandatory implementation of the mobility budget coming throughout the course of 2026, more questions appear:

• What about part-time employment? How to adapt your policy to keep the mobility budget fair and correct?
• Do part-time employees get the same mobility budget? Should it be reduced?
• And how do you make those decisions without opening the door to endless exceptions and uncomfortable conversations?

It does need to be thought through, but that doesn’t mean it’s complicated.

The Real Question Behind Part-Time Mobility Budgets

Technically, mobility budgets aren’t linked to working hours and are based on the reference value of the total cost of ownership (TCO). That gives organisations room to define their own approach. But many employees experience their benefits emotionally, which is why fairness matters.

When someone working four days a week receives the exact same mobility budget as a full-time colleague in the same role, questions come up. It’s not a question of legal, but more of something just feeling off and unfair. It’s therefore not obligated but some employers choose to adjust the mobility budget in line with employment percentage to align better with how people understand equity at work.

The pro-rata approach

Using the pro-rata calculation is easy to explain, easy to defend, and easy to apply at scale. If a role comes with a certain mobility budget, that budget would move in step with the contract: Someone working 80% gets 80% of the reference amount.

For example:

Take two employees with the same role and seniority:

• One works full-time, the other works four days a week. The role comes with a TCO of €680 per month.
• Following a clear pro-rata policy, the full-time employee receives the full €680, while the part-time employee working 80% gets €544.

It also creates a clear framework for the future. In case of change in the working hours (whether temporarily or permanently) the mobility budget adapts too. Consistency is what keeps policies credible over time.

How about personal contributions?

An employee previously paid extra for a specific car choice or usage (for example, when choosing a more expensive option than provided for in the car policy)? That money shouldn’t inflate the mobility budget later on, it should be deducted from the TCO. This nuance often gets overlooked. The budget should reflect what the employer actually financed, not the total lifestyle cost the employee chose at the time.

A personal contribution can look like:

• a one-off payment,
• a monthly deduction from net salary,
• a personal contribution to fuel or electricity costs (paid with personal card).

This detail might seem minor, but it makes a big difference in perceived fairness. Especially when employees start comparing.

Fair doesn’t always mean equal

Confusing “fair” with “the same for everyone” is one of the biggest mistakes made when designing a mobility policy.

It’s important to start from the same reference point for similar roles, and then adjusts objectively where it makes sense (such as employment percentage as mentioned). This allows full-time and part-time employees to be treated consistently without being forced into artificial equality.

If the logic is clear and transparent, employees will accept the outcome more easily.

Write the clear policy down

Most mobility budget issues come from bad communications and a lack of transparency, leading to assumptions.

Someone remembers how it worked “last time”. Another colleague heard something slightly different. This can escalate quickly to HR having to explain decisions that were never clearly defined in the first place. So what should it include?

A well-structure mobility budget policy should at least include:

• The definition of the mobility budget
• Your rules for part-time employees and calculations (e.g pro-rata)
• Definition of personal contributions and their potential deductions
• Fairness and equal treatment
• Indexation and promotions
• Management of the budget and its follow-up

Putting your mobility budget rules clearly and with full transparency in the policy, and other internal communications, changes that dynamic. You need help to start writing yours? Download our fully compliant mobility budget policy template.

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