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The Finnish Tax Administration has sent or sends a letter of instructions to companies between 9 February 2026 and 2 March 2026.
In December 2025, a legislative amendment entered into force allowing shares acquired in certain share exchange situations to be valued at their mathematical value prior to the share exchange in the acquiring company’s net worth. The effect of the change will first be seen in accounting periods ending on 8 December 2025 or after.
You received this letter because the Tax Administration’s records show that your company has been the acquiring company in a share exchange on or after 1 January 2017. Below you will find information on how you should take the legislative amendment into account when you file your tax return for tax year 2025 and after.
What kind of share exchanges does the amendment concern?
The amendment applies to share exchanges which have taken place on or after 1 January 2017 and in which the parties to the exchange were related (related-party share exchange). The association between the parties must have existed before the share exchange or be created as an immediate consequence of the exchange.
The parties are related if any of the following requirements is met:
- one party holds either alone or together with its related entities more than half of the other party’s capital or votes
- the same third party holds either alone or together with its related entities more than half of both parties’ capital or votes
- as a consequence of the share exchange, one party’s holding or voting power in the other party exceeds 75%.
Filing shares acquired in a related-party exchange on the tax return
When you file shares acquired in a related-party exchange on or after 1 January 2017, enter the combined mathematical value of the shares prior to the exchange on Form 8A.
When you file the tax return for tax year 2025, enter the combined mathematical value prior to the share exchange in field “Undepreciated acquisition cost for purposes of income tax” on Form 8A. In the tax return for tax year 2026, shares acquired in a related-party exchange are reported in a separate section.
The comparison value of the shares acquired in a related-party exchange is filed in the same way as before. The sum of the comparison values added together and reported on the form is compared with the combined undepreciated acquisition costs for purposes of income tax, which also include the combined mathematical value of the shares acquired in a related-party exchange prior to the exchange.
Determining the mathematical value
The mathematical value of the target company share acquired in a related-party exchange can be checked on the target company’s tax decision. Select the tax decision stating the mathematical value for the calendar year during which the share exchange took place. Tax decisions are available in MyTax from tax year 2017 onwards. If you need a mathematical value for an earlier tax year, request it from the Tax Administration.
Example: If the share exchange took place on 2 May 2019, for example, see the tax decision for tax year 2018 to find the mathematical value for 2019. Multiply the mathematical value in the tax decision by the total number of shares in the company’s possession acquired in the share exchange.
Effects on the taxation of dividend income
The legislative amendment also has an effect on the taxation of dividend income if a dividend can be drawn on or after 1 January 2026 and the company distributing the dividend has accquired shares in a related-party exchange on or after 1 January 2017.
If the shares acquired in a share exchange are valued at the undepreciated acquisition cost in the company’s net worth, the Tax Administration will adjust the mathematical value used in the taxation of dividend income. The changes to the taxation of dividend income are applied in the tax assessment for tax year 2026.
If the company wants to cancel a distribution of dividends due to the legislative changes, the distribution must be cancelled before the dividends could be drawn.
Effects on the taxation of share transfers
On account of the legislative amendmend, the acquisition cost used in the calculation of capital gain is determined in a new way if the transferred shares are acquired in a share exchange between related parties on or after 1 January 2026. The acquisition cost of the shares for purposes of tax assessment is considered to be the combined mathematical value of the shares prior to the exchange. If the related-party share exchange took place on or before 31 December 2025, the acquisition cost of the transferred shares is still the undepreciated acquisition cost for purposes of income tax. When the share transfer is filed, the acquisition cost for purposes of income tax is entered on Form 71A or 71B.