When do I need to file my Belgian income tax return?

The paper tax return must be filed by 30 June 2023. This means the tax return must hit the letterbox of the scanning centre in Jambes (near Namur) or in Ledeberg (near Ghent) on that day. Don't leave it to the last minute. Putting the tax return in the mail on the 28th may be too late. 

If you missed the deadline, you can still file online until 15 July 2023. Plan ahead; Tax-On-Web tends to get overloaded.

If you are too late, you cannot give a power of attorney to an accountant or a tax adviser anymore. He can only file online until 18 October 2023 if you areself-employed, a company director, or if you have overseas earnings or if you pay your spouse or civil partner a salary. However, on behalf of all accountants and tax advisers, please do not bring your shoebox with your payslips and tax documents on 15 October.

If you aren't living in Belgium, or if you have the expatriate tax status, the paper filing deadline for non-residents is much later, usually in the beginning of November (on paper) or, if you or your tax adviser file online, two weeks later. 

When do I receive my tax return? 

The tax authorities must send your tax return to you five weeks before the deadline. They will generally have been sent during the month of May. Tax-On-Web can already be accessed from the beginning of May. Non-residents will only be able to access Tax-On-Web from the middle of September.

It's 1 June and I haven't received my tax return yet

If you filed your tax return online last year, that is normal. Once you file online, the tax authorities assume that you want to continue filing online and they do not send you a paper tax return any more. In the past you could ask to receive a paper tax return the following year, as a sort of reminder. The tax authorities do not send them any more; that saves on postage.

If you want a paper tax return or if you have not received your tax return yet, you must contact your local tax office and ask them to send you a form. If you have difficulties locating your tax office, check page 2 of last year's tax bill (under ‘Calcul’), check the website of the Finance Ministry or call 0257 257 57. This is a call centre that answers most tax questions. 

This is also where you should go if you lost or misplaced your tax return. Do not use a photocopy of a friend’s tax return; that would only get you both in trouble.

I am late 

If you forget to file (or to sign online), you risk a fine between €50 and €1,250 and a penalty of 10% to 200% of the tax. The highest penalties are really for persistent repeat offenders. What is more important is that the taxman can just ignore your tax return when he assesses the tax.

More from our 2023 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 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. If you have a question, you can contact him by clicking on his name.