In general, foreign nationals from the European Economic Area (EEA) (i.e., EU member states, plus Iceland, Norway and Liechtenstein) and Switzerland do not need a work authorization/permit to be employed in Belgium. However, EEA and Swiss nationals must obtain a residence permit if their stay in Belgium exceeds three months. On top of that, Limosa and Dimona declaration requirements almost always remain applicable.

Non-EEA nationals that come to Belgium to work (economic migration) must obtain an authorization to work and to reside in Belgium.

When the period of employment in Belgium exceeds 90 days, a single permit is mandatory. This permit requires an application via the digital "Working in Belgium" platform including both the submission of the employment and the submission of the residence related application documents. First, the employment authority of the competent region will confirm whether the file is complete and admissible and if so, start its investigation. If the file is not complete, missing documents must be provided within 15 days (in principle) or else the request is declared rejected. If the submission is approved, the employment authority of the competent region must forward the file to the federal Immigration Office. The Immigration Office will then confirm whether the file is complete and admissible. If the file is not complete, missing documents must be provided within 15 days (in principle) or else the request is declared rejected. In principle, a final decision of approval (or rejection) must be taken by the Immigration authorities within 120 days or four months after the application file has been declared admissible and complete. This term can be extended by the Immigration authorities. If the employee resides abroad, a visa D must be applied for at the Belgian Embassy or Consulate in the employee's country of residence, and the employee must in principle order and collect the single permit and register in the local municipality's immigration register within eight working days upon arrival in Belgium. If the employee is already (lawfully) residing in Belgium, the eight-day period starts from the moment they are notified of the positive decision.

Where the period of employment in Belgium does not exceed 90 days (and in other very specific circumstances), the residence and limited duration work permits (work permit type B) are issued through distinct procedures resulting in two separate documents. In this case, once the employee receives a type B work permit, the employee may need to obtain an  entry and/or residence visa (for a stay in Belgium for less than 90 days within any given period of 180 days, depending on the individual's nationality: for example, citizens of the US, the UK, Australia, Canada, South Korea and Japan can enter Belgium based on their national passports, for other nationalities, such as citizens of India, China and Turkey, a type C Schengen visa is required). If required, an entry and/or residence visa should be applied for at the Belgian Consulate or Embassy abroad with jurisdiction over the latest place of legal residence (or at the external service provider with whom the Belgian Consulate or Embassy works). Within eight working days of arriving in Belgium, the foreign national must in principle register with the local commune that has jurisdiction over the intended place of residence (unless an exemption is applicable, e.g., under certain circumstances when the foreign national will be residing in a hotel).

Aside from economic migration, foreign nationals may also be granted automatic access to the labor market based on their specific residence situation, even if they did not come to Belgium for employment-related purposes. These specific residence situations are listed exhaustively in the Royal Decree of 2 September 2018 (e.g. students, refugees, family reunion).

The work authorization must be obtained prior to the start of employment. Working in Belgium without a valid authorization (or valid exemption) is considered a serious offense, subject to substantial criminal and administrative penalties.

The Belgian Act of 11 February 2013 introduced a complex mechanism of joint liability for principals and contractors for wage debts if the contractor/subcontractor employs illegal workers. Principals and contractors can be held liable for their subcontractors' unpaid wages (including taxes and social security contributions) to its illegal employees in Belgium. Joint liability immediately kicks in as soon as the principal/contractor becomes aware that its subcontractor is employing illegal employees. Since 1 January 2025, the Flanders region has tightened chain‑liability rules, following which principals and contractors who appoint a (sub)contractor who employs third-country nationals must (i) include a clause in the contract stating that the (sub)contractor will not employ illegal workers and (ii) request additional documents from the (sub)contractor. If these are not provided, further steps must be taken, such as informing the social inspection services. Since 1 January 2026, the Flanders Region introduced additional obligations in certain high‑risk sectors (construction sector, cleaning sector, meat sector and courier services).

Under the Belgian Act of 9 May 2018, employers have the following additional obligations when employing foreign employees (i.e., non-EEA nationals) in Belgium:

• To verify whether the foreign employee has a valid residence permit (or any other valid residence authorization) prior to engaging in any work
• To keep a copy of the residence permit/residence authorization available for the social inspection services during the employment period of such foreign employee
• To declare the start and end date of the employment via the Dimona or Limosa declaration (Employers who do not comply with these obligations can be sanctioned with a level 4 penalty, i.e., the highest criminal and administrative level of sanctions.)

The entity who employs illegal employees in Belgium must pay a salary equivalent to the salary owed to a legally employed worker in a comparable employment relationship. The entity is also liable to pay the taxes and social‑security contributions that would have been due had the person been legally employed (including any penalties for late payment and any administrative fines).

Apart from possible criminal and administrative sanctions and operating bans, employers who engage employees without a valid work permit and/or residence permit are also jointly liable for the payment of repatriation costs, lump-sum housing costs and healthcare for both the foreign national and that of their family members.