Specific measures against social fraud

A contractor may have social debts with the NSSO or tax debts with the FPS Finance. If so, you as the client are not allowed to pay the entire invoice to the contractor. In such cases, you have to retain a part of it and pass it on to the NSSO and/or FPS Finance.

What is meant by ‘Withholding obligation’?

Clients, contractors and subcontractors who have activities carried out as described below are required to check whether their (sub)contractors have social or fiscal debts. If this is the case, they have to withhold a certain percentage of the invoice amount and pass it on to the NSSO (for social debts) or the FPS Finances (for tax debts).

Which activities are affected by the withholding obligation?

The regulations on the withholding obligation on invoices cover:

• Works on immovable property (art.30bis of the law of 27 June 1969), with the exception of certain activities of agriculture, horticulture and forestry which are explicitly excluded from the area of application.
• Supply of ready-mixed concrete as referred to in article 1, a, fifth paragraph, twenty-eighth indent of the Royal Decree of 4 March 1975 on the establishment and determination of the name and competence of the Joint Committee for the Construction Industry and fixing the number of its members.
• Works falling under the Joint Committee for guarding and/or surveillance services (art. 30ter of the Act of 27 June 1969 - Royal Decree of 17 July 2013).
• Works in the meat sector (art. 30ter of the Law of 27 June 1969 - Royal Decree of 22 October 2013).

Social debts with the NSSO

If the contractor has social debts, the client has to deduct 35% of the invoice amount and transfer it to the National Social Security Office ( to account number BE76 6790 0001 9295 with BIC: PCHQBEBB).

Fiscal debts with the FPS FinanceIf the contractor has tax debts, the client hast to deduct 15% of the invoice amount and pay it on to the FPS Finance (to account number BE33 6792 0023 2046 with BIC: PCHQBEBB).

Consult the ‘Manual Withholding obligation’ for a step-by-step guide on how to proceed in detail.

You can use the Declaration of works to notify the NSSO and relevant inspection services of work being carried out on properties.

Which works do you have to declare?

For work on properties and the supply of fresh concrete (30bis), you have to submit the following declarations:

• - any ‘client – contractor contract’ of 5,000 euros or more (excluding VAT) with at least 1 subcontractor;
• - any ‘client – contractor contract’ of 30,000 euros or more (excluding VAT) with or without subcontractors;
• - work that is hazardous due to the presence of asbestos.

Work covered by the Joint Commission for Security and Locking Services and certain activities in the meat sector also have to be declared (30ter).

When should the declaration be submitted?

The declaration has to be submitted before work starts.

If it concerns works on a temporary or mobile construction site or asbestos removal works, the declaration has to be submitted at least 15 calendar days before the start of the works. You can access the online service Declaration of works on the page Declaration of works on the Social Security portal (in French). Select the button that is relevant to you in the column on the right.

Consult the ‘Manual Declaration of works’ for a step-by-step guide on how to proceed in detail.

‘Checkinatwork' is an online platform provided by the NSSO to ensure that employers register their workforce correctly.

What is Checkinatwork?

Checkinatwork is the online service for the attendance registration concerning the delivery of ready-mixed concrete, activities falling under the meat sector and for works on immovable property, with the exception of certain agricultural, horticultural and forestry activities that are explicitly excluded from the area of application. It concerns the registration of:

• anyone who carries out works on immovable property at a workplace with a total cost equal to or exceeding 800,000 euros;
• anyone who carries out activities related to meat preparations or meat products and the slaughter or cutting of hoofed animals, poultry and rabbits in establishments subject to the approval (approvals, authorisations and prior registrations) of the Federal Agency for the Safety of the Food Chain (FASFC).

Via Checkinatwork, employers and contractors register the presence of their own employees, their subcontractors and their independent subcontractors. Employees and independent subcontractors can also register themselves on their own in the system.

Registration must be made daily and before the person carrying out the works starts work.

Workplaces covered by the compulsory attendance registration via Checkinatwork must be declared in the Declaration of Works (in French).

Access Checkinatwork on the Working in Belgium website.

Check In and Out at Work is the NSSO's online service for recording presence at work in selected sectors. For the time being, you can use the online service for cleaning activities.

What is Check In and Out at Work?

As from 1 September 2024, the recording of the start and end of activities and rest breaks will be mandatory for every employee performing certain cleaning activities. These are only 'activities whose purpose is to clean a property on behalf of a third party' and whose declaration is subject to the conditions of the threshold amounts applicable to all works of the 'immovable property' type, i.e.:

• 30,000 euros without a subcontractor;
• 5,000 euros with 1 subcontractor;
• no limit for 2 or more subcontractors. Registration therefore becomes mandatory when a declaration of works (in French)

Employees, self-employed persons, temporary workers and trainees self-register their presence at the workplace in real time. As an employer, you cannot do the registration. However, you must provide registration resources. You have a choice of channels, and you may also combine a number of channels.

There are two types of registration: ‘in’ and ‘out’. Registration 'in' should be done when the person performing the work starts the work. Registration 'out' should be done at the end of the activity. Rest breaks must also be recorded.

As an employer, you can access the registrations of your own employees and those of your subcontractors. You have access via the online service Check In and Out at Work on Working in Belgium.

In addition to consulting the registrations, you can also report an error in a registration. Contact the NSSO within 30 days of the registration date to request a change. You have to provide the necessary documents.

Access to Check In and Out at work

To access the secure online service Check In and Out at Work as a company, your company must be registered with the Crossroads Bank for Enterprises.

You also need an approved digital key, i.e. itsme, eIDAS or a username/password with a code via a mobile app or email (‘TOTP’).

We will explain the digital keys below:

1. itsme: If you have a Belgian electronic identity card (eID), you can use this digital key. F
   or more information, please visit the itsme page of the CSAM help centre.
2. eIDAS: If you don't have a Belgian ID card but you do have another recognised electronic proof of identity, you can use that digital key. To find out whether your electronic proof of identity authorises you to log in, click on ‘Log in with an EU-recognised electronic proof of identity’. You will then get an overview of which member states already have an electronic proof of identity.
   If you are logging in with eIDAS for the first time, you will need a European electronic means of identification, an email address and a phone number. If you don't have a Belgian national registration number or BIS number, a number will be created.
   More information can be found on the eIDAS page of the CSAM help centre.
3. E-mail TOTP: Your country doesn't support the digital keys itsme or eIDAS and/or you don't have a Belgian national identification number (BIS number)? Then make an appointment with Sigedis, the partner of the social security institutions for personal identification. Please make the appointment on the belgianID-website.
   After checking your documents, Sigedis will determine whether you already have a BIS number. If you don’t have one, Sigedis will create a number for you. During your video call, Sigedis will help you to obtain a digital key.

Log in to CSAM with your company registration number, your BIS number and your digital key. As the legal representative of your company, you can appoint yourself as Chief Access Manager to manage access to your online services. As Chief Access Manager, you determine which employees have access to Check In and Out at Work. You can also appoint employees as access managers to assist you with administration.

The procedure information on this page was funded by the European Union.

Funded by the European Union – NextGenerationEU. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or European Commission. Neither the European Union nor the European Commission can be held responsible for them.

Social Security Contact Centre

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