Corporate - Tax administration

Last reviewed - 10 January 2024

Taxable period

The fiscal year is generally the calendar year. A company having an accounting period other than the calendar year is taxed for the accounting period or the accounting periods ending during the calendar year.

Tax returns

A company must file a CIT return within four months from the end of the month during which the accounting period ends. As a general rule, companies must file a CIT return electronically after 1 November 2017.

For potential tax refunds, taxpayers should submit their account number to the tax authorities electronically.

Payment of tax

Income taxes are levied as prepayments during the fiscal year. Advance tax payments for companies are collected in two or 12 instalments during the fiscal year. If the total amount to be paid is not more than EUR 2,000, the instalments are due in the third and the ninth month of the accounting period. If the total amount to be paid exceeds EUR 2,000, the instalments are due monthly (due date is the 23rd day of each month).

Taxpayers may apply for amendments to advance taxes levied (increase, decrease, or abolishment) until tax assessment has been completed (within ten months from the end of the fiscal year at the latest). Application for amendments to advance taxes should be filed electronically.

Tax authorities may, without application, levy or increase advance taxes within two months from the end of the fiscal year. Decrease or abolishment of advance tax payments may be levied by the tax authorities (by or without taxpayer’s application) until tax assessment has been completed.

Interest on late payment will be calculated starting from the first day of the second month after the fiscal year has ended until the due date of each for the following payments that are due on that day or after:

  • advance tax payable
  • outstanding tax (i.e. if the final tax exceeds advance taxes paid and thus additional payment will be levied by the tax authorities), and
  • tax payable due to tax amendments.

The YLE tax is included in the advance tax payments.

Tax audit process

Tax audits are performed at irregular intervals by tax auditors, who are entitled to examine the accounts of a company and to request additional information necessary to the examination. Generally, the taxpayer receives an advance notice of an audit from the tax authorities.

Statute of limitations

The time to claim for reassessment of CIT has changed from fiscal year 2017.

From 2017 and onwards, the general time to claim for reassessment of CIT is three years starting from the subsequent year after the fiscal year (i.e. calendar year 2019 will be open for reassessment until 2022).

Prior to fiscal year 2017, the general time limit for statute of limitations was five years starting from the year after the tax assessment year (i.e. calendar year 2016 is open for reassessment until 2022).

In addition to the general three-year rule, the Finnish tax authorities may also rectify taxation after the three-year time limit in case certain criteria are met (in such cases, time limit would be extended to four or six years). In case of the taxpayer being accused for a crime, the appeal time is linked to the criminal justice process.

Appeal process

The appeal process has also changed from 1 January 2017 onwards. The primary appeal authority will always be the Tax Adjustment Board, regardless of the type of tax. The taxpayer may appeal to the Tax Adjustment Board within the general three-year time limit.

After receiving a decision from the Tax Adjustment Board, it can be appealed within 60 days to the Administrative Court.

The possibility to appeal the Tax Adjustment Board’s decision directly to the Supreme Administrative Court on prejudice grounds remains unchanged and it will cover all tax types.

Topics of focus for tax authorities

Current issues of special focus for tax audits are transfer pricing and PEs.


MyTax is a system where taxpayers can, for example, request a prepayment or additional prepayment and file self-assessed tax returns (e.g. VAT or employer's contributions). In MyTax, taxpayers can also file CIT returns and make claims for adjustment.

MyTax and other portals of the Finnish Tax Authorities can be accessed by using authorisations. More detailed instructions on how to obtain access and authorise third parties in are provided on the website.