The short answer
The main rule is no — unlisted shares generally cannot be held in a Swedish Investment Savings Account (ISK). An ISK is designed for financial instruments traded on a regulated market or an MTF (Multilateral Trading Facility).
Why not ISK?
The Swedish Tax Agency requires assets in an ISK to have a continuous market valuation, which is difficult with unlisted holdings where there is rarely a current market price. The standard taxation on an ISK is based on the assets' value at specific measurement dates, making unlisted holdings problematic from a tax perspective.
The exception: Endowment Insurance (Kapitalförsäkring)
Some niche players and insurance companies offer the possibility to hold unlisted shares within an endowment insurance wrapper.
- Advantage: You avoid the 25% capital gains tax upon a potential sale and instead pay an annual standardized tax based on the holding's value.
- Disadvantage: Significantly higher and more complex fees. Some insurance providers charge fixed annual fees per holding, and external valuation of the company may be required, which costs money.
What is the alternative for most?
The most common and straightforward way for private individuals to own unlisted shares is via a standard stock and fund account (AF), also known as a custody account (aktiedepå/värdepappersdepå).
- Taxation occurs only upon sale (or dividend).
- The capital gains tax for unlisted, unqualified shares (non-closely held) is typically 25% (5/6 of unlisted gains are taxed at 30%).
- No ongoing standardized taxes regardless of how the company is valued.
Summary
The default choice for unlisted shares is a traditional custody account where you pay 25% tax on any profit upon future sale. ISK is not allowed. Endowment insurance is technically possible via certain specialized providers, but the fees often consume the tax advantage unless significant amounts are involved.