Claim for adjustment of income tax (Form 3308) – Instructions

The form Claim for adjustment of income tax can be used to request an adjustment to your income tax. This form can also be used to appeal against an adjustment made on the Tax Administration's initiative. Please also attach the necessary supplement forms to the claim. Check the form-specific instructions to see what information you must provide in each supplement form. The supplement forms are specified in these instructions.

A claim for adjustment can be submitted electronically via MyTax. A written claim for adjustment can also be submitted using this form, or on a separate document in your own words. If you submit a claim for adjustment in your own words, print out this form and use it as a cover sheet. Also attach to the claim for adjustment any other supporting documents which you have not previously delivered to the Tax Administration. Send the claim for adjustment to the address marked on the form. The form and further information are available on the 'Forms' page.

Claims for adjustment are processed by the Assessment Adjustment Board. In some cases, a claim for adjustment may also be processed as a complementary tax decision.

By when should a claim for adjustment be submitted?

A claim for adjustment can be submitted after the completion of your tax assessment. Check the end date of your tax assessment and the appeal period in your tax decision.

You can submit a claim for adjustment within 3 years of the start of the calendar year following the end of the tax year. Read more about Time limits for submitting a claim for adjustment or Time limits for appealing against a tax adjustment decision made on the Tax Administration's initiative.

Notwithstanding the above, a claim for adjustment can always be made within 60 days of receiving the tax decision.

The claim for adjustment must arrive at the Tax Administration by 4.15 pm on the end date of the appeal period. Please note: we recommend that you check the local tax office's opening hours. If the last day for submitting a claim for adjustment is a public holiday or a Saturday, the claim for adjustment can be submitted to the Tax Administration on the following business day.

1 Taxpayer identification

Fill in your name, personal identity code or Business ID, street address and telephone number. The name and personal identity code or Business ID of the applicant must always be provided in the claim for adjustment form.

 If you have authorised an agent to provide further information on the claim for adjustment, or if you want us to deliver the decision directly to your agent, fill in the agent's name, address and telephone number in the marked boxes.

If necessary, attach a letter of authorisation for tax representation to the claim for adjustment form. To authorise someone to act on your behalf, use the Tax Administration's Form 3818 (Letter of authorisation for tax representation), or provide authorisation in your own words in a separate written document. Attorneys and public legal advisers do not need to be authorised with a letter of authorisation for tax representation.

2 The claim

The year(s) which the claim concerns

Enter the tax year which the claim for adjustment concerns. If you are claiming an adjustment covering several tax years, enter all of the years which your claim concerns.

Grounds for the claim for adjustment

Check the box, in accordance with the matter your claim for adjustment concerns. You can check more than one box.

Travel expenses

If your claim concerns

Expenses incurred in acquiring or maintaining income If your claim concerns

  • expenses incurred in acquiring or maintaining wage income, other non-wage compensation for work or benefits, attach Form 50A Earned income and deductions.
  • capital income-related expenses incurred in acquiring or maintaining income, attach Form 50B Capital income and deductions.
  • grant-related expenses incurred in acquiring or maintaining income, attach Form 10 Grants.
  • expenses incurred in acquiring or maintaining income allocated to the production of income based on notes, attach Form 11 Production of income.

Rental income/Losses incurred in rental operations

If your claim for adjustment concerns the taxation of rental income or expenses allocated to rental income, attach the appropriate form from among the following to the claim for adjustment:

Tax credit for domestic costs

If your claim concerns

Capital gains/capital losses

If your claim concerns

Types of securities include publicly traded shares and book-entry securities. In certain situations, capital refunds are also taxed in accordance with the tax rules for capital gains. Other property includes real estate units, shares in a housing company or real estate company, shares in a non-publicly traded company, and a percentage share in a general partnership or limited partnership.

Interest on loans

If your claim concerns the deduction of interest on a loan from capital income, fill in Form 50B Capital income and deductions.

The types of interest include

  • Home loan interest
  • First-time buyer's home loan interest
  • Interest on loan relating to acquiring or maintaining income
  • Interest on loan for acquiring a share in a business partnership
  • Shareholder's interest payments relating to an agricultural partnership's loan

Details of business or agricultural activities

If your claim concerns details of a business or agricultural activities,

Details on agricultural activities

If your claim concerns the taxation of forestry activities, attach Form 2C Tax return – forestry (in Finnish or Swedish only).

Foreign income

If your claim for adjustment concerns the taxation of earned income or capital income received from a foreign country, attach the appropriate form from among the following to the claim for adjustment:

If you are requesting the progressive income taxation of earned income, attach Form 6148 Request for progressive taxation of earned income.

Other grounds

Check the box if your claim for adjustment is based on grounds other than those described above. Attach the appropriate form, as needed, to the claim for adjustment. For example, if you are submitting the claim form in order to

If you need further guidance, call the Tax Administration's telephone service numbers.

What tax adjustments are you claiming?

In this section, describe the types of adjustments you are claiming for your taxation.
If you are presenting more than one claim, number the claims accordingly.

3 Grounds for the claim

In this section, describe the grounds for submitting your claim.
If you are presenting more than one claim, use the numbers corresponding to the claims to number the grounds in question.

If necessary, continue on a separate attachment. Remember to write your name and personal identity code on the attachment.

Claim for enforcement injunction or interruption of tax collection

Check the box if you are applying for an enforcement injunction or the interruption of tax collection while the claim for adjustment is being processed. You are eligible to apply for an enforcement injunction or the interruption of tax collection if you have unpaid back taxes for the tax year for which you have submitted the claim for adjustment.

The tax will continue to incur late-payment interest and a possible surtax during the injunction or interruption. If your claim for adjustment is fully or partly rejected, the remaining tax will fall due with late-payment interest.

Date and signature

Remember to sign the claim for adjustment form.

Page last updated 3/4/2024