PUBLISHED ON 01/12/2023

Welcome to the Brexit Brief! In this newsletter for UK citizens living in Brussels or thinking of moving here, we will explore some of the more complicated aspects of life after Brexit. Each edition will start from a puzzling everyday question, using it as a chance to explore the rules that UK citizens should know about.

Case Study 9: “I am a freelance consultant in the UK and I want to spend time in Brussels working for clients based there. What permits do I need to live and work in Belgium, and what will this move mean for my tax and social security affairs?”

Recent editions of the Brexit Brief have focused on income tax and social security for UK citizens who move to Brussels to work as employees. However, many people who move to Brussels work in a more flexible arrangement as a “freelancer” of some kind (best referred to as a “self-employed worker” in the Belgian context. In this edition, we revisit the topics of tax and social security from the freelancer’s perspective, but first we address the formalities for residence and the right to work.

Note: This article is intended for UK citizens wanting to do freelance work in Belgium as post-Brexit third country nationals. If you already hold an M-Card or N-Card because you were resident or doing cross-border work before the end of the Brexit transition period, this advice does not apply to you.

Throughout the article, it is important to distinguish two interpretations of the case study above:

  1. A self-employed person based in the UK who gets a client in Brussels and visits or moves here briefly to complete that one mission. In this case, you will be working here temporarily, before returning to your personal and professional base in the UK. This could make you a kind of posted worker if you need to stay in Belgium for some time, but you might just be an individual on a business trip if the project is short and the activity requires no other approval.
  2. A self-employed person who wants to move to Brussels and be based here, working for multiple clients and building new client relationships with a long-term perspective.In this case, you would be a long-term migrant who wants to build their home and career here in Brussels.

Keep these two situations and your own plans in mind as you read the rest of the article, as the rules and procedures can be quite different.

Immigration formalities for freelancers

For Belgian immigration purposes freelancers, consultants, service-providers, small business owners, etc, will all typically be considered as “self-employed workers” (indépendant.es/zelfstandige). They carry out a profitable professional activity without being bound to a specific employer by an employment contract. However, the distinction between employees and the self-employed in Belgium is subtly different from what is applicable in the UK, for example when it comes to board members of companies. We therefore recommend that you carefully ascertain your legal status, as different rules apply to employees.

If you are planning on carrying out self-employed activities in Belgium as a UK national, you will first need to assess which authorisations to work you need. Then you can assess which residence documents (if any) you should apply for.

For work authorisation you need to ask yourself:

  1. Do I need a work permit (for self-employer workers this is a so-called “professional card”), or is my planned activity exempted from this requirement?
  2. Do I need to submit a posted worker notification, depending on the sector where I will be active?

You might need to undertake one, both or neither of these two work authorisation processes.

Do I need to apply for a professional card or does an exemption apply?

In principle UK nationals should acquire a professional card as work authorisation to undertake self-employed activities in Belgium. However, if your professional activities and your stay in Belgium will not extend beyond 90 days in any 180 day period, you might be exempted from the requirement to obtain a professional card either based on Belgian legislation or the EU-UK Free Trade and Cooperation Agreement.

The grounds for an exemption are fairly generous, and apply for example for the following activities:

  • meetings and consultations
  • technical, scientific, and statistical research and design
  • market research
  • training seminars
  • trade fairs and exhibitions
  • sales
  • purchasing
  • after-sales or after-lease service
  • commercial transactions
  • tourism
  • translation and interpretation

Moreover, exemptions are in place for journalists, artists, and athletes.

If your activity is not on this list, you must apply for a professional card. Likewise, if your activities in Belgium will extend beyond 90 days in any 180 day period, you must apply for a professional card.

Thinking of our two scenarios above, the consultant intending to move to Brussels for the long-term and recentre their career here will surely need a professional card because they intend to be here for more than 90 days. However, the self-employed UK citizen who is only coming here for a few missions in a given 180-day period, and whose activity falls under the exempt category, may be able to undertake their work in Brussels without a professional card.

If you do need a professional card, note that the eligibility conditions differ between the Regions of Belgium (Brussels, Flanders and Wallonia). The competent region is the one where your activities will mainly be carried out or where your business will be officially established if you decide to establish yourself in Belgium. The most important requirement to obtain a professional card is the need to demonstrate the economic value of your activity or its social, cultural, artistic, or sporting importance. For a detailed overview of the eligibility criteria and a detailed step-by-step guide for the application process, please consult this page.

Do I need to submit a posted worker notification?

You will need to submit a posted worker notification (also called “Limosa”) if your business is established in the UK and you are temporarily providing a service in Belgium in a sector that is considered as high-risk. The sectors currently identified as high-risk are:

  • Construction
  • Meat processing
  • Cleaning

In the scenarios above, this requirement would only apply to the first case, where the self-employed worker is based in the UK but comes to Brussels for a specific mission in one of the high-risk sectors. Anyone coming to Brussels with the aim to set themselves up as a self-employed worker in these sectors would not need to submit a posted worker notification, because their business would be established in Belgium.

Which residence documents will I need as a self-employed working in Belgium?

Once you have understood any work authorisation requirements, you can also assess whether you need to apply for any visa and corresponding residence permit.

If you need to be in the Schengen area for more than 90 days in any 180-day period, you will need a residence permit. For UK citizens coming to Belgium for their professional activity, this means applying for a long-stay visa (visa type D) at the Belgian embassy in your country of residence. You can apply for this visa on the basis of your professional card, once the application for the professional card is approved. (Remember, once your activity goes over the 90-day limit, you need a professional card even if the activity itself is on the exempt list.) With this D-Visa you can register with the local authorities (town hall) in Belgium and obtain a residence permit. This permit will be valid for the duration of your professional card, which is usually two years.

How will my social security work if I do self-employed work in Belgium?

Let’s start with the scenario of the short-term or “posted” freelancer. If a UK national who is a self-employed in the UK wants to temporarily provide freelance services in Belgium, they can remain covered by the UK social security system. You should apply for an A1 certificate (certificate of social security coverage) from HMRC for a period of up to max 24 months. After that period, you would become subject to Belgian social security for self-employed workers.

If you are going to pursue your activity as a freelancer simultaneously in both UK and Belgium, you will normally be subject to social security in your country of residence. This applies so long as you perform a substantial part of your activity (25% of turnover, working time, number of services etc.) in that country. Otherwise, you will be subject to social security in the country where you have the centre of interest of your freelance activities. The time period to be looked at is, in principle, the next 12 months. This means that a UK self-employed worker who remains resident in the UK while working in Belgium temporarily needs to retain at least 25% of their freelance activities in the UK if they want to avoid shifting to the Belgian social security system.

It is also possible that you have a main professional activity in the UK as an employee, while you also have a separate smaller activity as a self-employed worker or freelancer in Belgium. In such a case, you will be subject only to the social security system of the country of employment (the UK in this example), even for the revenue of the self-employed activity in Belgium.

In all of the above situations, you will continue to build up your entitlements to social security benefits and pensions in one country only. For temporary stays, the NHS may issue to you a Global Health Insurance Card (GHIC) to cover urgent medical care. If you become a resident of Belgium while still remaining subject to UK social security, you will also need to obtain an S1 certificate from the NHS and register with a health insurance fund in Belgium (mutuelle/ziekenfonds). There is no waiting period for entitlement to medical care in Belgium, so you are covered straightaway.

These cases show that UK-based self-employed worker can undertake temporary missions in Belgium while remaining subject to and covered by the UK social security system. However, remember that you still need to ensure you are in line with all the work permit and immigration rules discussed above.

If, on the contrary, you are a UK national who wants to move to Belgium and start working as a freelancer or self-employed worker as your main professional activity, you will first have to complete any immigration requirements for work and residency authorisation (see above).

Once you are entitled to perform your activity in Belgium, you must sign up to a social insurance fund for the self-employed and pay social security contributions in Belgium before starting the self-employed activity. If not, the National Institute for the Social Security of the Self-Employed (INASTI/RSVZ) will send you a reminder, giving you 30 days to join a fund of your choice. You will then start to build up social security rights in Belgium for medical care, pensions, child benefits, incapacity for work and sickness.

Self-employed and freelancers must actively pay social security contributions themselves. The contributions are calculated based on the annual net taxable income and are payable on a quarterly basis (upon receipt of the payment notice from the social insurance fund). If you have just started your activity and the income is still uncertain, you will have to pay a statutory minimum contribution. These quarterly provisional payments range from approximately €93 (for a secondary activity) to approximately €841 (for a principal activity). Later, once your activity is up and running, the maximum quarterly contribution is approximately €4820. For further information, please refer to this document which presents contribution rates and amounts as of 2023.

After two years from the start of your activity, the tax administration will notify your social insurance fund about your actual annual net professional income. At that time, the fund will calculate the final social security contributions you owe. If you over-paid social security contributions, the difference will be refunded. Vice versa, if you under-paid contributions, you will be asked to pay the difference.

For further general information on social security for the self-employed, please feel free to consult the website of INASTI/RSVZ.

And what about income tax?

From a tax point of view, the term "freelancer" as such is not defined in the double tax treaty between Belgium and the UK. Therefore, for this discussion we will stick to the assumption that you are an individual performing work (service provision) in Belgium, not through a company, on a self-employed basis.

Whether you are mainly based in the UK or Belgium, the concept of "permanent establishment" is crucial to determining in which country your income may be taxed. Under the double tax treaty, your income for a given activity will be taxed where you have a permanent establishment.

The double tax treaty also provides a definition of the term "permanent establishment": a fixed place of business through which the business of an enterprise is wholly or partly carried out. This is the case, for example, if the freelancer has an office in Belgium where they undertake their work. Designating a permanent establishment is always a question of fact and the situation must therefore be assessed by a tax expert on a case-by-case basis according to the exact details of each case.

A permanent establishment is characterised by a certain degree of permanence. The OECD Commentary gives the example of a painter “who, for two years, spends three days a week in the large office building of his main client. In that case, the presence of the painter in that office building where he is performing the most important functions of his business (i.e. painting) constitute a permanent establishment of that painter.” In this case, the income from these painting services would be taxable in the country where the client’s office is situated.

Thus, a freelancer can remain a fiscal resident and taxpayer in the UK, but undertake work in Belgium in such a way that they have a permanent establishment here. The income related to this permanent establishment will then be taxed in Belgium. However, the Belgian tax paid on the freelancer's professional income will be credited against any taxes due in the UK.

In rather exceptional cases, a freelancer will have multiple permanent establishments. After all, we are dealing here with a physical person who, by his very nature, is limited in time and resources. This is different for companies that can have permanent establishments in several countries simultaneously.

Merely undertaking occasional work is not enough to speak of a permanent establishment. As a matter of principle, the income from services undertaken without a permanent establishment remains taxable in the state of residence. Therefore, if a freelancer only did occasional short missions in Belgium, they might avoid having a permanent establishment here at all. In this case, all their income would be taxed in the UK.

Of course, the reverse situation can be true as well. If we return to the second scenario, a freelancer who makes Belgium their main professional and personal base would most likely become a fiscal resident here. Their income would in principle be taxable in Belgium. However, if they retain a permanent establishment in the UK, then the income related to that activity would be taxed in the UK.

What next?

In conclusion, UK citizens who are not protected by the Withdrawal Agreement and who want to do self-employed work in Belgium need to think carefully about immigration formalities, work authorisation, social security and income tax. In this article, we have only given a first indication of the issues and rules to consider. Every freelancer’s situation is different, and you would not have an employer to do any of the legal and administrative work for you. Moreover, we have not addressed any of the procedures involved in getting set up as a freelancer or small business owner in Belgium.

Nevertheless, none of this makes it impossible for UK citizens to undertake freelance work in Brussels as short-term missions or on a more permanent basis. Many professionals are still working between Brussels and the UK, or moving here to set up a new venture and find clients. All the same, it is advisable to speak with legal and/or accountancy experts before you start work.

If you have any further questions regarding this topic, you may contact the specialists who helped draft this edition of the Brexit Brief:


Welcome to the Brexit Brief! In this newsletter for UK citizens living in Brussels or thinking of moving here, we explore some of the more complicated aspects of life after Brexit. Each edition starts from a puzzling everyday question, using it as a chance to present the rules that UK citizens should know about. Some newsletters are relevant for M-Card holders, some for those arriving after Brexit, and some for all UK citizens. This newsletter is part of a project funded by the EU’s Brexit Adjustment Reserve, in which we are also developing a series of webinars and an online Brexit HelpdeskTo receive this monthly newsletter straight to your inbox, sign up today!


These pages, webinars and newsletters have been developed in a project funded by the EU’s Brexit Adjustment Reserve.

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