In addition to the joint and several liability of project owners, contractors and subcontractors for the illegal employment of third-country nationals, they may also be held liable for the social security and tax debts of the parties with whom they collaborate. Since 1 January 2026, as a business owner in the construction and cleaning sectors, you are obliged to check whether your client or (sub)contractors have social security and/or tax debts with the authorities and to withhold these amounts from the invoices you receive. If you fail to do so, you may be held jointly and severally liable for these debts.
- Purpose of the withholding obligation
All too often, busy self-employed people fail to register with a social insurance fund or neglect to pay their social security contributions. Naturally, this places an unfairly heavier burden on business owners who do fulfil their social security obligations than on ‘social security evaders’. In order, on the one hand, to ensure that entrepreneurs are taxed equally in the social security sphere and, on the other hand, to safeguard the social security system, the legislator has introduced a withholding obligation following the 2024 registration requirement.
- Withholding obligation: What is it?
The withholding obligation can be defined as the legal obligation whereby a client paying an invoice to a contractor or service provider in the construction or cleaning sector must, under certain conditions, withhold a portion of the invoice amount and pay it directly to the competent authority. This obligation applies where the contractor or service provider has social security or tax arrears at the time of payment.
Before paying their invoices, the client or contractor must check whether the contractor or professional project manager has any social security or tax arrears. If this is the case, they are legally obliged to withhold the prescribed amount and pay it on. If the client fails to comply with this obligation, they may be held jointly and severally liable for the amounts not withheld.
If you become aware of any tax or social security debts, you must deduct the following amounts from the invoice total:
- 15% of the invoice total, excluding VAT, in the case of tax debts owed to the FPS Finance;
- 35% of the invoice total, excluding VAT, in the case of social security debts owed to the RSZ, PDOK or FBZB;
- 15% of the invoice amount, excluding VAT, in the case of social security debts owed to the RSVZ;
- A maximum of 50% if there is an accumulation of tax and social security debts.
Payment must be made directly to the relevant government authorities.
- Practical implementation
Before paying your outstanding invoices, always check your business partner’s social security or tax debts.
By carrying out a quick and simple check via “checkinhoudingsplicht.be”, you can verify whether you can pay the full invoiced amount to the invoicing party, or whether you must withhold a percentage and transfer it to the government authorities.
If a withholding obligation applies, you can find all the relevant information on this same portal by simply clicking on the red status indicator. Once the required amount has been withheld, the remainder of the invoice can be paid directly to your creditor.
As has already become clear regarding chain liability, doing business in the construction sector today involves much more than simply providing high-quality services. As a sound and forward-thinking entrepreneur, it is essential to make the necessary preparations, to be aware of your legal obligations and to carefully check who you are working with.
The withholding tax obligation also emphasizes that a professional partnership does not end with the signing of a contract. Those who comply with these obligations correctly not only limit legal and financial risks but also build a reliable and sustainable business. After all, good entrepreneurship today means not only craftsmanship on site but also the thoughtful management of the administrative and legal obligations that go hand in hand with it.
At Adverit Legal, we support entrepreneurs with these obligations, so that they can focus fully on delivering high-quality services. By taking a proactive and strategic approach, we optimize the professional running of your business and help you avoid financial setbacks.
