How do I report Interactive Brokers gains to the Finnish Tax Administration?

Capital gains are reported in MyTax (OmaVero) under Capital gains and losses. For each sale you need the acquisition price, sale price, dates and fees in euros — PnlTrack calculates these automatically.

Do I need to convert currencies to EUR?

Yes, both the buy and the sell are converted to euros at the trade-date ECB rate. PnlTrack does the conversion on the correct dates automatically.

Why does the Flex Query report have so many rows?

A single order is often filled in pieces at different prices (partial fills), so it appears as many rows. That is normal — PnlTrack merges the partial fills into one trade.

Should I use the deemed acquisition cost?

Choose between the actual acquisition cost and the deemed cost (20% or 40%) whichever gives the smaller taxable gain. PnlTrack compares both for you.

Interactive Brokers tax report in Finland (2026)

Interactive Brokers does not file Finnish taxes for you — the responsibility is yours. This guide covers what to report, how to convert currencies to EUR and how PnlTrack produces ready figures without Excel.

General information, not tax advice. Verify your own situation or consult a professional.

Interactive Brokers is a foreign broker and does not send data to the Finnish Tax Administration for your pre-completed return. In practice the full reporting burden is on you: every sale, dividend and fee must be reported yourself in MyTax (OmaVero) with correct euro amounts. This guide walks through what to report and how to calculate it correctly.

What you must report

As an IB investor you report every item realised during the tax year. These fall into four groups:

Capital gains and losses — the result from selling shares, ETFs and derivatives. A gain is taxable capital income; a loss is deductible.
Dividends — foreign dividends are reported gross, with withholding tax accounted for separately.
Interest income — for example on cash balances or lent-out shares.
Trading fees — commissions and other direct costs are added to the acquisition cost or deducted from the sale price.

More on dividends on the page about dividend taxation in Finland, and on derivative specifics in taxation of options and derivatives.

Converting currencies to EUR

On an IB account trades are often in dollars or other currencies, but the tax return is always in euros. Both the purchase and the sale are converted to euros at the trade-date exchange rate — not the year-end rate nor an average. The Tax Administration accepts the European Central Bank (ECB) daily rate. This means the same trade can produce a euro-denominated gain even if the result in the trading currency is exactly zero, if the rate moved between buy and sell.

Acquisition cost and the FIFO principle

When you have bought the same share in several lots and sell part of it, you must decide which lot is deemed sold. Finland applies the FIFO principle (first in, first out): the oldest holding is sold first. The acquisition cost includes the purchase price and the buy commission, both converted to euros at the rate on the day of purchase. Tracking FIFO by hand is laborious when there are dozens of lots.

Worked example

Here is a concrete example. You bought 10 shares at 100 USD each when EUR/USD was 1.10. The acquisition cost is 1,000 USD ÷ 1.10 = 909.09 € (excluding commissions). You later sell the same lot at 120 USD each when EUR/USD was 1.05. The sale price is 1,200 USD ÷ 1.05 = 1,142.86 €. The capital gain is 1,142.86 − 909.09 = 233.77 €, reported as capital income. Note that in dollars the gain was 200 USD, but in euros it differs because of the FX move — this is exactly where most manual-calculation errors come from.

Flex Query import and why there are many rows

IB's Flex Query is a report you can configure to include all executed trades, dividends and fees in a machine-readable format. PnlTrack imports it automatically. One thing often surprises people: a single order may appear as many rows. This is entirely normal — a large order is often filled in pieces (partial fills) at different prices and even different seconds. The software correctly merges these partial fills into one trade for the calculation, so you do not need to worry about the row count.

The deemed acquisition cost and the 1,000 € exemption

Instead of the actual acquisition cost you may deduct the deemed acquisition cost: 40% of the sale price for holdings owned over 10 years and 20% for shorter holdings. Pick whichever option gives the smaller taxable gain. In addition, if the combined sale price of all disposals during the tax year stays under 1,000 €, the gains are tax-free and need not be reported. More on losses on the page about deducting capital losses.

MyTax and deadlines

Capital gains are reported in MyTax under Capital gains and losses. The pre-completed return arrives in spring and there is an annual deadline for supplementing it — check your own date in MyTax. In practice you need to gather, for each sale, the acquisition price, sale price, dates and fees in euros. You can estimate the tax in advance with the capital gains tax calculator.

How PnlTrack does it for you

Imports your full IB history automatically via Flex Query and merges partial fills correctly
Calculates acquisition costs on the FIFO principle and converts currencies at ECB daily rates
Suggests the cheaper option between actual cost and the deemed acquisition cost
Handles dividends, withholding tax and derivatives in the same view
Produces ready tax-report figures in one click

A week of March work shrinks to a few minutes, and the risk of calculation errors drops substantially.