K4 Form Basics
Last updated: June 13, 2026
A practical overview of what the Swedish K4 form covers, how the sections work, and which general rules matter before you file.
The K4 form (Bilaga K4) is the supplementary Swedish tax form used to report the sale of securities, such as shares, bonds, derivatives, and certain other assets held outside ISK and kapitalforsakring accounts.
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What is reported on the K4?
- Section A: Listed shares, equity options, warrants, and similar securities.
- Section C: Bonds, currency, and other interest-bearing instruments.
- Section D: Crypto, unlisted shares, commodities, and other assets that belong in the “other assets” bucket.
Understanding Form Columns (Section A)
| Column | Meaning |
|---|---|
| Antal | Quantity sold |
| Namn | Security name |
| Forsaljningspris | Total sales proceeds after commissions |
| Omkostnadsbelopp | Acquisition cost using the relevant cost-basis method |
| Vinst / Forlust | Calculated gain or loss |
How K4 totals map to Inkomstdeklaration 1
K4 Section -> Inkomstdeklaration 1
| K4 Section | Total gains | Total losses |
|---|---|---|
| A | Field 7.4 | Field 8.3 |
| B | Field 7.4 | - |
| C | Field 7.2 | Field 8.1 |
| D | Field 7.5 | Field 8.4 |
Pre-filled amounts still matter
The 20% rule (schablonmetoden)
For listed shares, you may choose schablonmetoden instead of using the actual historical cost basis. Under this rule, the acquisition cost is treated as 20% of the sale proceeds.
Schablonmetoden example
If you sell listed shares for 10,000 SEK, the deemed acquisition cost becomes 2,000 SEK and the taxable gain becomes 8,000 SEK.
Not for every asset class
Frequently asked questions
Do I report ISK transactions on K4?
No. Transactions inside an ISK are not reported on K4. ISK is taxed through the account regime instead of individual gains and losses.
Where does crypto go?
Crypto is generally reported in K4 Section D. Schablonmetoden does not apply there.
What if I do not know my acquisition cost?
Then you need more transaction-level history, supporting documents, or a fallback rule that actually applies to the asset. Start with Why You Need Transaction-Level Data and then use the practical workflow guide if you are filing through Skatteguru.
Related Articles
- K4 Filing with Skatteguru — Handle incomplete data, dashboard review, and SRU export
- Why You Need Transaction-Level Data — Why yearly gains-and-losses summaries are not enough for K4
- K-forms Overview — See how K4 fits into the broader Swedish declaration system
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