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Understanding the paper Belgian income tax return

00:54 01/05/2021

Let’s open that brown envelope; what will you find?

The tax return

You cannot miss it; it is the document that has little text and columns in red. You can find the model here in Dutch and in French. It resembles a lotto form, and just like a lotto form it will be scanned. Just seeing it is quite disheartening, with columns and codes to complete. It is all a question of putting the right number or X with the correct code. And you get these codes from the draft form.

The draft                                               

This is where you start the draft to help you file your tax return. There are three (slightly) different tax forms for people who live in Brussels, in Flanders or in Wallonia, all in two or three languages  (Brussels (NL) / Flanders / Wallonia). This is because some tax incentives or tax reductions, e.g. for mortgages, cheques service, renovation … are given by the regions. And separate tax returns help avoid unnecessary mistakes. Whether you receive a Brussels, Flemish or Walloon tax return depends on the region where you were registered with the commune on 1 January 2021.

It's a guide to filling out the tax return per type of income or expense. You need to work out what income goes in what box and with which code and then you copy the codes and the information in the tax return. If you work as a freelancer, a self-employed professional or the director of a company, you also need “part 2” (Dutch/French). Note that there are no different models per region.

When you copy the codes on the tax return, a few suggestions from the taxman:

  • use a black or dark blue pen,
  • write within the blocks, in capitals and in clear digits.
  • don't put in any unnecessary mentions or even ‘nil’.
  • don't strike out mistakes, use correction fluid.
  • If you have to give more information, don't write it by hand, the scanners have difficulties with handwriting.

The green page

If you want to attach any documents justifying deductions or tax credits, you should attach them to the green page. It has all your information and it is scanned with the attachments. You aren't obliged to file these documents; you may just keep them at home until the taxman specifically asks to see them. However, if you want to give additional information or if you have made a calculation of allowable expenses, I suggest that you attach a printed page with the information so that this information is on file immediately.

The explanation

The tax authorities used to send a booklet explaining the tax rules with your tax return. They don’t do that any more. You can find the explanation in Dutch or French online for each of the three regions (Brussels, Flanders and Wallonia).  

The envelope

When you have finished copying all the codes in the tax return, make sure that both spouses or partners sign it. And when you put it in the envelope, the address of the tax office goes behind the window.  

Do not forget the stamp. Postage isn't free.

More from our 2021 income tax guide

  1. When do I need to file my Belgian income tax return?
  2. Online or on paper?
  3. Filing online
  4. Understanding the paper tax return
  5. Checklist: What documents do you need?
  6. The return in detail
  7. Belgian income tax: There's nowhere to hide
  8. A guide to cross-border taxation
  9. Belgian income tax returns for families
  10. Help! Where to get assistance with your tax return
  11. Understanding your Belgian income tax bill
  12. How do I appeal?
  • This guide was written by Marc Quaghebeur, an international tax lawyer and partner at Cabinet DAVID. It is a general introduction based on current understanding of the law. It is not to be taken as a suitable alternative for individual advice.



Hello, I was wondering if anyone could answer this: my mother has received a Belgian tax return request for the first time this year, having received a Belgian pension for over ten years. We used to live in Antwerpen and are now based in the UK.
Thank you.

Nov 27, 2020 13:07
MQ Jun 11, 2021 08:47