Claim for adjustment of income tax

This guidance is for individual taxpayers, self-employed business operators, and agricultural and forestry operators.

If you need to make additions or corrections to the pre-completed tax return you received in Spring 2019, you can submit the changes in MyTax or on paper forms.

How to make corrections online

How to make corrections on paper

If you notice something that must be changed after your tax assessment has ended, you must file a claim for adjustment to the Tax Administration’s Adjustment Board. For many individual taxpayers, the assessment for 2018 ends as early as late May 2019.

You can file a claim for adjustment to the Adjustment Board after your assessment has ended.

When does tax assessment end?

You can see the date when the Tax Administration completes your tax assessment on your tax decision. Starting in 2018, the assessment process ends earlier than before for most taxpayers.

Starting in tax year 2018, everyone has their own personal end date for the tax assessment process. As a rule, the assessment is completed in the time between July and October of the year following the tax year. You can see the end date for your tax assessment on MyTax or on your tax decision. The assessment of spouses always ends at the same time.

Please note that the end date of your assessment may be postponed if you or your spouse make changes to your pre-completed tax returns or if the Tax Administration receives some other information that affects your assessment. In this case, you will receive a new tax decision containing a new assessment end date.

The tax assessment process for tax year 2017 ended on 31 October 2018 for all taxpayers. In previous years, the end date of the tax year’s assessment process was always 31 October in the following year.

Taija receives her pre-completed tax return for 2018 in the spring of 2019. She must file any changes to the tax return by 14 May 2019. The details on the tax return seem to be correct, so she does not make any changes to them.

However, Taija notices later that there is a mistake in her commuting expenses. The pre-completed tax return includes a tax decision which states that the end date of Taija’s tax assessment is 19 June 2019.

If Taija notices the mistake before the end date, she can correct it by filing new details in MyTax or on the travel expense form 1A. If Taija notices the mistake only after the assessment has ended on 19 June, she can file a claim for adjustment in MyTax or on the paper form “Claim for adjustment of income tax”.

How to file a claim for adjustment?

You can file a claim for adjustment electronically in MyTax. You can see certain identifying details for 2012–2017 tax decisions (decision date, decision number, tax type) in MyTax. Full contents of the decisions are available in MyTax starting with tax year 2018.

You can also make the claim on paper by filing the form Claim for adjustment of income tax (3308e) or by writing a free-form claim.

What details must be included in the claim for adjustment?

A claim for adjustment must always include

  • the name and personal ID of the person making the claim
  • the tax year that the adjustment concerns
  • the changes that you claim
  • the grounds for these changes.

Enclose any relevant documents that support your claim, unless you have already sent them to the Tax Administration. If you wish that the decision is sent to your representative, please say so on your claim and give the representative’s address.

When must the claim for adjustment be filed?

You can make a claim for adjustment as soon as the tax assessment process has ended. Before the end of tax assessment, you can make additions and corrections to your tax return in MyTax or on separate paper forms.

Starting with tax year 2017, claims for adjustment of income taxation can be made within 3 years from the beginning of the calendar year following the tax year.

If your claim concerns tax years 2013–2016, you must file the claim within 5 years from the beginning of the calendar year following the tax year in question.

If the last day of the calendar year is a Saturday or Sunday, the deadline for the claim is extended to the next business day. Check the tax year and the instructions for making a claim for adjustment in your tax decision.

Deadlines for claims for adjustment for each tax year
Tax year Deadline when the claim must be at the Adjustment Board
2013 31 December 2019
2014 31 December 2020
2015 31 December 2021
2016 2 January 2023
2017 31 December 2020
2018 31 December 2021
2019 2 January 2023

The appeal period may be shorter if the adjustment decision is initiated by the Tax Administration

Your tax assessment may be adjusted by the Tax Administration, if the Tax Administration receives information that affects your taxes after the assessment process has ended. You can appeal an adjustment decision made by the Tax Administration by filing a claim for adjustment to the Adjustment Board.

Remember to check the length of the appeal period in the instructions enclosed with the decision. The appeal period is either 3 or 5 years, depending on whether the decision was made before or after 1 January 2017.

Read more about adjustment decisions by the Tax Administration and about appealing them (available in Finnish and Swedish, link to Finnish).

If you include new information in your claim for adjustment

If you provide some completely new information in your claim for adjustment, the Tax Administration will assess it and make a supplementary tax decision. This information can be new income details, a new deduction, or other relevant information that had not been included in your tax return or had otherwise not been accounted for in your tax decision.

Starting with tax year 2018, a new procedure for supplementary tax decisions is applied. You can appeal a supplementary tax decision by filing a claim for adjustment with the Adjustment Board. The appeal period is the same as for original tax decisions. The appeal period is stated in the instructions for appeal enclosed with the supplementary tax decision.

Only claims submitted within the appeal period will be considered

You must make your claims for adjustment to the Tax Administration before the appeal period ends. Remember to allow enough time for postal delivery to ensure that your documents have arrived at the Tax Administration by the last day of the appeal period. Claims that arrive after the appeal period has ended will not be considered.

Taxes must be paid even if an appeal is pending

You must pay your taxes on their original due dates even if you have made a claim for adjustment for them. However, you may request the Tax Administration to prevent or postpone any recovery of tax by enforcement while your claim is being processed. If the recovery of the tax is prevented of postponed, the original overdue amount will continue to accrue penalty interest or late-payment interest as normal.

Appeals to the Administrative Court and Supreme Administrative Court

If you disagree with the Adjustment Board’s decision, you can file an appeal to the Administrative Court.

  • Starting in tax year 2017, the appeal period is 60 days from the date when you received notice of the Adjustment Board's decision.
  • Appeals concerning tax years 2013–2016 must be filed within 5 years from the beginning of the calendar year following the end of the tax year’s assessment. If your appeal concerns a tax adjustment decision initiated by the Tax Administration and dated 1 January 2017 or after, the appeal period to the Administrative Court is 60 days from the date when you received notice of the Adjustment Board’s decision.
  • Always check the length of the appeal period from the instructions enclosed with the decision.

Appeals must be delivered to the Administrative Court by the end of the appeal period. You can also file an appeal in the e-service of the Administrative and Special Courts (available in Finnish and Swedish, link to Finnish).

Check the addresses of Administrative Courts (www.oikeus.fi).

If you disagree with the ruling of the Administrative Court, you can appeal to the Supreme Administrative Court, if the Supreme Administrative Court gives you permission to do so. Appeals must be submitted within 60 days from notice of the Administrative Court’s ruling.

Appeals to the Administrative Court or Supreme Administrative Court may be subject to a charge.

More information on the fees charged by courts of law (www.oikeus.fi).

ple 1: The assessment of taxes for individual taxpayers was completed 31 October 2016. Claims of adjustment with regard to tax year 2015 must arrive at the Tax Administration by 31 December 2021.   

Example 2: Claims of adjustment with regard to tax year 2017 must arrive at the Tax Administration by 31 December 2020. 

Example 3: The Tax Administration adjusted your 2014 taxes on its initiative on 15 January 2017.  You have time to file a claim of adjustment regarding this decision by 31 December 2017. 

Example 4: The Tax Administration adjusted your 2013 taxes on its initiative on 22 March 2017.  You have 60 days to file a claim of adjustment regarding this decision, counting from the date when you received notice of it. 

Example 1: The assessment of taxes for individual taxpayers was completed 31 October 2017. Claims of adjustment with regard to tax year 2016 must arrive at the Tax Administration by 2 January 2023.  

Example 2: Claims of adjustment with regard to tax year 2017 must arrive at the Tax Administration by 31 December 2020.

Example 3: The Tax Administration adjusted your 2015 taxes on its initiative on 15 June 2017.  You have time to file a claim of adjustment regarding this decision by 31 December 2018.

Example 4: The Tax Administration adjusted your 2014 taxes on its initiative on 22 March 2018.  You have 60 days to file a claim of adjustment regarding this decision, counting from the date when you received notice of it.