How We Handle Same-Day Stock Option Sales on Your Tax Declaration

Some of you have noticed that when you have multiple events on a single day, the order of the events has a significant impact on your tax liability. This can be surprising.

When you exercise stock options (or vest RSUs) and sell the shares on the same day, you might notice that your trade confirmations only contain the date, but not the time of day that the transaction occurred. This makes it difficult to determine the chronological order of transactions, and Skatteguru needs to make an assumption.

Skatteguru assumes that all purchases (option exercises or RSU vests) happen first, and then all sales happen afterward. This is a simplification, and may not reflect the actual chronological order of your transactions. You can correct this by setting execution times.

Important: You can now set the exact execution time for your transactions (BUY, SELL, ESOP_EXERCISE, RSU_VESTING, etc.) in Skatteguru. This ensures that transactions are processed in the correct chronological order when you have multiple transactions on the same day. For E*TRADE users, we have created a step-by-step guide on how to find the execution time and enter it into Skatteguru:

• Finding Execution Time in E*TRADE Orders - Learn how to find the exact execution time for your trades and enter it into Skatteguru

By setting the correct execution times, you ensure that Skatteguru can accurately calculate which shares were sold first, leading to correct cost basis and capital gains calculations. If no time is provided, Skatteguru defaults that transaction to 00:00:00 UTC for ordering.

• The actual chronological order of transactions should be used to compute the average cost at each sale.
• Mis-ordering the transactions when reporting could alter your declared capital gain and would not reflect the economic reality.
• Use the time editing feature in Skatteguru to set the correct execution time for each transaction. This ensures accurate processing of same-day transactions.
• If you're unsure about the execution order, check your broker statements or trade confirmations for the exact times.

When you don't know the exact execution order of your same-day transactions, Skatteguru can show you the range of possible tax liability. Use the "Tax Range Explorer" setting in your calculation preferences to explore how different ordering assumptions affect your taxes.

Important: This tool is for exploring the range of potential tax liability only. If you're uncertain about which setting applies to your situation, please consult a tax advisor or consider using an Öppet Yrkande (Open Disclosure) in your tax declaration. This explains to Skatteverket exactly how you calculated your values, which may provide protection from the 40% tax surcharge (skattetillägg) in case of disagreements.

You can find the Tax Range Explorer in your Tax page settings. The slider lets you explore three scenarios:

• Maximum Tax: Assumes the ordering that results in the highest tax liability
• Balanced: A middle-ground calculation
• Minimum Tax: Assumes the ordering that results in the lowest tax liability

In February 2026, we reached out to Skatteverket to clarify how same-day transactions should be handled. Specifically, we asked whether intra-day transactions should be processed step by step in chronological order (using timestamps), or whether all purchases and sales on a given day should be aggregated first and then netted against each other.

To illustrate, consider this example: on March 15, you exercise stock options for 100 shares at 50 SEK at 10:00, sell 50 shares at 12:00, and exercise another batch of 100 shares at 80 SEK at 14:00. Under the chronological approach, the average cost at the time of the sale is 50 SEK (since the second exercise hasn't happened yet). Under the aggregation approach, you would first combine all exercises into a single pool (average cost 65 SEK) before applying the sale.

Skatteverket confirmed that chronological order is correct — you should process transactions step by step in the order they occurred, even when they happen on the same day. This means the timestamps of your transactions matter, and you should use them to determine the correct average cost at each point of sale.

This section provides a deeper look at the Swedish tax law underpinning the chronological ordering of same-day transactions, for those who want to understand the legal foundation.

The Relevant Law: Inkomstskattelagen (IL)

The governing legislation is the Swedish Income Tax Act (Inkomstskattelag 1999:1229), commonly abbreviated as IL. The key chapter is Chapter 48, which governs the disposal of equity rights and debt instruments (Avyttring av delägarrätter och fordringsrätter), including how capital gains and losses are calculated when selling shares.

While IL Chapter 48 requires chronological ordering of transactions, it does not explicitly mention how to handle multiple transactions on the same day. The law speaks in terms of dates, not times of day. This creates an ambiguity: should same-day transactions be aggregated, or should they be sequenced by their actual execution time when more than one trasaction takes place on a specific date?

Skatteverket's Interpretation

Skatteverket's confirmation that chronological order applies even within a single day is consistent with the spirit of the law — the average cost method is designed for step-by-step precision. Their guide on computing average cost basis is structured for entering transactions in chronological order, which implicitly supports intra-day sequencing.

However, it is worth noting that this interpretation comes from Skatteverket's tax advisory service, not from published binding guidance or case law. If you have a complex situation or large amounts at stake, you may want to consider requesting a formal advance ruling (förhandsbesked) for your specific case, or consult a professional tax advisor.

Practical Implications

The key takeaway is that if you have multiple acquisitions and disposals on the same day, the guidance is that you should document the execution times and process them in order. If timestamps are unavailable and the ordering is ambiguous, err on the side of caution and consider reaching out to Skatteverket or a tax advisor for guidance specific to your situation.