Hold on: you don't pay tax on your gains?
That's the main thing people get wrong about ISK. You don't pay capital gains tax on profits. You don't declare individual trades. You don't report dividends. Instead, Sweden charges you a flat annual tax based on the total value of your account, called the schablonintäkt (standardised income). Whether your portfolio is up 30% or down 20%, you pay the same rate on your balance.
That's the trade-off. In a good year it can be cheaper than capital gains tax. In a bad year you still pay. Most long-term investors find it simpler and cheaper overall, which is why ISK has become the default savings vehicle for Swedish retail investors.
The big change in 2026: the free allowance doubled
From 1 January 2026, the first SEK 300,000 of your ISK balance is completely tax-free. That limit was SEK 150,000 in 2025. The doubling was introduced by the government to encourage smaller savers and is applied automatically. Your bank does the calculation and reports the correct figure to Skatteverket. You don't do anything extra.
In practice this means anyone with a balance below SEK 300,000 pays nothing in ISK tax for 2026. That covers a large share of Swedish ISK holders. If you're above it, you only pay on the portion that exceeds the limit.
How the rate is set each year
The ISK tax rate isn't fixed. It's recalculated every year based on Sweden's government borrowing rate, the statslåneräntan, as measured on 30 November of the preceding year. The formula adds 1 percentage point on top of that rate.
For 2026: statslåneränta was 2.55% on 30 Nov 2025, so schablonränta = 3.55%. Tax = capital base × 3.55% × 30% = 1.065% of your capital base.
2025 vs 2026 side by side
| Item | Income year 2025 (declared spring 2026) | Income year 2026 (declared spring 2027) |
|---|---|---|
| Statslåneränta (Nov 30) | 1.96% (Nov 2024) | 2.55% (Nov 2025) |
| Schablonränta | 2.96% | 3.55% |
| Effective tax rate | 0.888% | 1.065% |
| Tax-free threshold | SEK 150,000 | SEK 300,000 |
| Tax on SEK 500k balance | ~SEK 3,106 | ~SEK 2,130 |
| Tax on SEK 1M balance | ~SEK 7,549 | ~SEK 7,455 |
The higher schablonränta in 2026 is partly offset by the doubled tax-free limit, which is why smaller balances see a significant reduction while larger balances end up roughly similar to last year.
What counts as your capital base?
Your kapitalunderlag (capital base) isn't just today's account value. It's the average of your account balance at the start of each quarter (1 January, 1 April, 1 July, 1 October), plus any deposits you made during the year. Your bank calculates this and sends it to Skatteverket automatically. You'll see it in your tax return as a pre-filled figure.
One thing worth knowing: withdrawals don't reduce your capital base during the year. Only the opening values of each quarter count. So if you withdrew a large sum in February, that money still counted towards your Q1 opening value and your capital base will be higher than your current balance suggests.