New withholding requirement as of May 1, 2026

Clients and contractors who have work carried out in the construction or cleaning sector must withhold 15% of the invoice amount (excluding VAT) when paying the contractor or subcontractor if the latter has outstanding social debts as an independent.

These works relating to immovable property in the construction and cleaning sectors are listed in Article 30bis of the Act of 27 June 1969. They concern the same activities as those subject to the registration obligation for working partners and helpers with the Crossroads Bank for Enterprises (via My Enterprise) as from 1 July 2024.

This obligation is in addition to the already existing withholding obligation towards the National Social Security Office (NSSO) and the Federal Public Finance Service (FPS Finance).

The withholding obligation does not apply to individuals who have work carried out exclusively for private purposes.

The withholding applies to overdue social security debts exceeding EUR 2,647.00 (2026) that arise under the social status of the self‑employed. This includes debts of the partners and directors of the contractor or subcontractor (in the case of companies), as well as those of self‑employed contractors or subcontractors and their helpers.

The withholding also covers any overdue annual flat‑rate social contribution for companies owed by the contractor or subcontractor.

It does not concern debts that are covered by a properly observed repayment plan with the social insurance fund or the bailiff.

Through www.checkinhoudingsplicht.be (only available in Dutch and French) and the company number, you can check whether a withholding obligation applies. This online application can be used as a basis to prepare the withholding. You will then receive a structured reference to be used for the payment.

This withholding obligation does not apply where a withholding obligation already exists, either for the National Social Security Office (NSSO – 35%) or for the Federal Public Finance Service (FPS Finance – 15%).

In any event, overdue social security debts arising under the social status of the self‑employed remain fully recoverable by the social insurance fund.

If this new obligation is not complied with, a penalty of 15% of the invoice amount (excluding VAT) may be imposed, with a maximum of EUR 10,578.23 (2026). The National Institute for the Social Security of the Self‑Employed (NISSE) supervises compliance with this new obligation.

In the construction and cleaning sectors, checking subcontractors for withholding obligations with regard to the NSSO and FPS Finance via the same website is often standard practice. The same level of diligence is also expected for this new withholding obligation. However, experience shows that smaller companies in these sectors do not always consistently verify whether a withholding obligation applies.

This is even more the case for clients outside these sectors who have work carried out by companies from the construction or cleaning sector, without always checking whether or not a withholding obligation applies.

Through the above‑mentioned website, each contractor can check for their own company whether a withholding obligation applies.
To obtain information about the amount and payment arrangements of their debts under this new withholding obligation, they must contact their own social insurance fund (and not the NSSO).

As of May 1, 2026, more info will be available on the Social Security Enterprise website (only available in dutch and french).

This website will also include a dedicated FAQ on the withholding obligation.

It is also important to note that the date on which government decisions regarding invoice withholdings for social and tax debts are updated will be harmonised. These updates will take place monthly, on the Friday following the last Thursday of the month.