How ISK Taxation Works
An Investment Savings Account (ISK) is a standardized taxed account. Unlike a traditional fund account, you do not pay capital gains tax on individual profitable sales. Instead, you pay an annual percentage based on the total value of your account.
Investments involve risk.
New Tax-Free Thresholds for 2026
From January 1, 2026, the government has introduced a tax-free threshold for savings in ISK and Capital Insurance.
- Tax-Free Limit: Savings up to SEK 300,000 are completely tax-free per person.
- Combined Holdings: This applies to the total value across all your ISK and Capital Insurance accounts.
How to Calculate Your Tax
The tax is calculated based on a “standardized income,” which is then taxed at the capital gains rate of 30%.
1. Determine the Capital Base
The capital base is the average value of your ISK during the year. To calculate this:
- Add the value of your ISK at the beginning of each quarter (Jan 1, Apr 1, Jul 1, Oct 1).
- Add all deposits made during the year.
- Divide the total sum by four.
2. Calculate Standardized Income
The standardized income is the capital base multiplied by the government borrowing rate (as of Nov 30 of the previous year) plus 1 percentage point.
- For 2026: The effective tax rate is 1.065% on capital exceeding the 300,000 SEK threshold.
Frequently Asked Questions
Do I need to declare my trades?
No. Quartal automatically calculates your standardized income and reports it to the Swedish Tax Agency. It will appear pre-filled on your annual tax return.
Should I keep cash in my ISK?
We recommend against keeping large amounts of uninvested cash in an ISK for long periods. Even idle cash is subject to the annual standardized tax, meaning you are paying tax on capital that is not earning a return.
