A new approach to fiscal control is in the making in Belgium. In the Netherlands, horizontal supervision, where fiscal control is exercised based on an agreement between the tax authorities and the tax payers (or their accountant or tax advisors), has been an option for years.

As a result of this year’s Summer Agreement, horizontal supervision is also on the horizon for our country.  This marks a tremendous change from the current fiscal control approach, which is solely exercised by the tax authorities and which only takes place after a tax return has been submitted.

What is horizontal supervision?

Horizontal supervision means that the taxpayers (and more likely, their accountants or tax advisors) are responsible for conducting their own own tax audits. It is based on the notion of increasing cooperation between the taxpayer and the tax authorities.

This of course, requires clear agreements between all parties involved, with clear quality standards. These agreed-upon standards then have to be followed. As such, an accountant or tax advisor will have to refuse performing services requested by the taxpayer-client if these are in conflict with the quality requirements.

Associations and their members

In implementing horizontal supervision, agreements will be made on several different levels. First of all, all-encompassing agreements will be made with the professional associations (BIBF, IAB, …).  These agreements will set forth strict quality requirements. The associations will also be called upon to ensure that members effectively agree to provide the required quality.

Additionally, accountants and tax advisors will be bound by a service provider’s agreement, by which they will specifically agree to meet the quality requirements.

To ensure a proactive approach, participating members will also be called upon to engage with the tax authorities.

Participating businesses

A business can participate in the horizontal supervision approach by working with an accountant or tax advisor who meets the requirements to do so.  To participate, the business will need to sign a participation form.

Of course, participating in this horizontal supervision system does not exclude a control by the tax authorities. Nothing prevents them from checking that the agreements are in fact being complied with.

Advantages of participation

There are clear advantages of participating in the horizontal control system. Participating businesses will get a clear overview of their tax situation more quickly. Also, any questions or concerns can be discussed with the tax authorities in advance. Business will have more certainty as a result.

Additionally, participating businesses should be less often subjected to fiscal control. They would only be controlled in the event they are part of the few selected.  Exactly how this selection will be determined (and exercised) is to be seen.

No participation requirement

There is no requirement to participate in the horizontal supervision approach. Accountants and tax advisors can choose whether or not they want to opt in.

Businesses will also have the choice. If they would prefer not to participate, they can opt for an accountant who has also chosen not to do so. However, if Belgium approaches this like the Netherlands has, we expect increased controls for non-participating taxpayers.


Horizontal supervision requires mutual trust, on both the side of both the taxpayer and the tax authorities. If this mutual trust is missing, horizontal supervision is likely doomed.