After filing your return you realise that you have made a mistake.

If you filed your return via Tax-on-web, you can correct it yourself until 15 July 2023. Please note: you can only correct your return once.

In all other cases it is best to contact your tax office as quickly as possible to correct your mistake. In this way you can ensure that the corrections you have requested are taken into account when your tax assessment is determined.

In the event of a material error (e.g. incorrect addition of two sums, duplication, error when transferring an amount), double taxation or new information that you could only submit after the deadline due to circumstances beyond your control, the administration will correct your situation on request. There is no need to lodge an official objection. Contact us to transmit new elements to our service.

You have five years in which to do this, starting from 1 January of the assessment year (e.g. in the case of the 2023 assessment year (2022 income), the period starts on 1 January 2023 and runs until 31 December 2027).

If you do not agree with the result of the tax calculation as indicated on your assessment notice, you need to lodge an objection. In this you should specify the information that you believe to be incorrect.

You can lodge a complaint within one year of the sending of the tax assessment notice:

• on paper: as from the third working day following the date of sending
• by electronic means only: as from the day it is made available via eBox and MyMinfin

Concerning the tax assessment notices sent in 2022: the one-year deadline also applies if the original six-month deadline has not expired by January 1st 2023.

Examples of deadlines

• Tax assessment notice sent in paper form:
  • January 4th 2023: the deadline started on January 9th 2023 and will end on January 8th 2024.
  • June 28th 2022: the deadline started on July 1st 2022 and ended on January 2nd 2023 (December 31st being a Saturday and January 1st a public holiday, the deadline was extended to the next working day). The new deadline applies and will end on June 30th 2023.
• Tax assessment notice made available via e-Box and MyMinfin:
  • June 30th 2022: the deadline started on the same day and expired on December 29th 2022. The new one-year deadline does not apply.
  • October 3rd 2022: the deadline started on the same day and should have ended on April 3rd 2023 (April 2nd being a Sunday). The new deadline applies and will expire on October 2nd 2023.

The objection must relate to an amount of tax that has been officially determined, i.e. an assessment that has been entered on the assessment roll. In other words, you can only lodge an objection if you have already received an assessment notice.

After all, it is only from this point on that you have an interest in lodging an objection, as the enforceability of the assessment roll means that the amount of the tax liability has been fixed.

You must lodge an objection:

• either online via MyMinfin (your personal tax file)
• or in writing, in which case you must sign it yourself or have it signed by your authorised representative. You do not need to send the objection by registered post. A letter sent by ordinary post is sufficient.

You have to submit your claim in French, Dutch or German. For instance, if you have received your tax assessment notice in French, we recommend that you submit your claim in French. Unfortunately, it is not possible to use English (your claim will not be accepted).

You should lodge the objection with the competent Centre, the address of which can be found on your assessment notice.

In your objection you must indicate which assessment notice you are objecting against. You can only lodge an objection if you have received an assessment notice.

Your objection must be substantiated. This means that you need to present factual and legal arguments to support it.

During the objection procedure you can request mediation from the Tax Mediation Service.

If the objection period (one year from when your assessment notice was sent) has expired, in some cases you still have the option of requesting ‘official relief’ (‘ontheffing van ambtswege’/‘dégrèvement d’office’).

You can submit a request for ‘official relief’ in the event of:

• a material error (e.g. incorrect addition of two sums, duplication of an amount, error when transferring an amount)
• double taxation
• new information that you could only submit after the deadline due to circumstances beyond your control
• the marital deduction erroneously not being applied
• the tax-free allowance being too low (e.g. because no consideration has been given to your dependent children or the disability of a dependent child)
• the reduction for pensions and substitute income erroneously not being applied

You can ask the administration to correct your situation by submitting a request. There is no need to lodge an official objection. Contact us to transmit new elements to our service.

You have five years in which to apply for ‘official relief’, starting from 1 January of the assessment year (e.g. in the case of the 2022 assessment year (2021 income), the period starts on 1 January 2022 and runs until 31 December 2026).

You can also request mediation from the Tax Mediation Service during this procedure.

Initially, you only have to pay the amount corresponding to:

• either the tax due on the income that you have declared or approved
• or the tax most recently determined in your name, if you have not filed a return.

The official who handles your objection will calculate the amount immediately due and inform you of this as quickly as possible.

If you do not pay the amount that is considered to be immediately due, the collector may institute legal proceedings.

If you do not agree with the portion that is immediately due, you can bring an action before the competent court of first instance (which is determined based on the location of your tax collection office).

Yes. You have two options:

• either bring an action before the court of first instance
• or ask your Regional Director to defer collection of the amount that is immediately due.

If you do not pay this amount, the collector may take legal action. This may involve seizing household effects or attaching your earnings. Such action will only be taken up to an amount that corresponds to the portion immediately payable. The seizure/attachment serves as a guarantee in respect of the portion of the taxes that you are contesting.

As a precautionary measure, the collector may also register a mortgage interest in immovable property belonging to you.