Crypto losses in Sweden: K4 reporting and the 70% deduction

Sweden does not offset cryptocurrency gains and losses one for one. Skatteverket requires gains and losses to be calculated using the average cost method, reported separately in K4 section D, and allows only 70% of the crypto loss as a deduction. A sale for fiat, token-for-token exchange, payment with crypto or certain lending disposals can trigger reporting. The simplified annual K4 totals do not remove the need for a complete transaction-by-transaction calculation: the taxpayer must still prove Swedish-krona proceeds, average acquisition cost and wallet transfers for each cryptocurrency.

Identify every disposal before calculating losses

Skatteverket treats a sale, exchange and payment with cryptocurrency as a disposal. Swapping BTC for ETH therefore requires a SEK disposal calculation for BTC and creates acquisition information for ETH. The absence of a bank withdrawal does not postpone the Swedish event.

Staking, lending and DeFi may contain both income and disposals. A reward receipt is not automatically a spot sale, while exchanging a token for an LP or receipt token can require separate analysis. See the Sweden DeFi guide.

Use genomsnittsmetoden, not FIFO or the standard method

For cryptocurrency, Skatteverket uses the average cost method. The average acquisition cost for units of the same cryptocurrency changes with acquisitions and is applied when units are disposed of. The official page also states that the schablonmetoden—the standard percentage method available for some securities—cannot be used for cryptocurrency.

Calculate the pool across the taxpayer's holdings of the same cryptocurrency rather than treating each exchange account as an independent taxable owner. Own-wallet transfers move units without creating new cost. A transfer fee paid in crypto can itself dispose of units and must be handled consistently.

Average-cost example

An investor buys 1 ETH for SEK 20,000 and later 1 ETH for SEK 30,000, excluding this simplified example's fees. The pool contains 2 ETH at SEK 25,000 each. Selling 0.5 ETH for SEK 10,000 uses SEK 12,500 of average cost and produces a SEK 2,500 economic loss. The remaining 1.5 ETH keeps SEK 37,500 of pooled cost.

A falling exchange “average entry price” is not proof of the Swedish pool because it may omit other wallets and prior acquisitions. Rebuild the full history. The Sweden crypto tax guide explains the SEK conversion and event scope.

Only 70% of a crypto capital loss is deductible

Skatteverket states that cryptocurrency losses are deductible at 70%. In the example above, the SEK 2,500 loss produces a deductible loss amount of SEK 1,750 for the capital-income calculation. This is not a 70% refund and does not mean the taxpayer receives SEK 1,750 in cash.

Gains and losses must remain separate because they do not offset fully. Do not net a SEK 10,000 gain and a SEK 10,000 loss to zero in the report. The full gain and the 70%-deductible loss feed the broader capital-income calculation, which can include other items and deficit-reduction rules.

• calculate every disposal before aggregation;
• separate profitable and loss-making transactions by cryptocurrency;
• report the full loss basis/proceeds in K4 as instructed;
• allow the tax return calculation to apply the 70% rule;
• do not mix business, derivative or ordinary-income losses into spot totals.

An unrealised decline has no disposal and therefore no K4 capital loss. Lost access, theft, bankruptcy claims and worthless tokens require evidence of a recognised disposal or other applicable rule; a dashboard value of zero is insufficient.

K4 section D and simplified annual reporting

Skatteverket directs individuals to K4 section D for cryptocurrency. The electronic Income Tax Return 1 service can calculate the gain or loss from selling price and acquisition cost. The official guidance allows simplified reporting of total gains and total losses, but separate reporting is still required for each cryptocurrency.

For profitable transactions in one token, sum selling prices and corresponding average costs and report the difference as gain. Do the same separately for loss transactions and report the loss. Keep the detailed calculation because Skatteverket can request it even though the K4 displays aggregate totals.

1. calculate average cost before each disposal;
2. convert proceeds and costs to SEK at the relevant date;
3. group gain disposals separately from loss disposals;
4. prepare separate K4 section D lines by cryptocurrency;
5. retain the detailed ledger behind each total;
6. reconcile K4 totals to the full tax return.

The Sweden K4 filing guide explains the return workflow.

Fees, derivatives and business activity

Allocate exchange and blockchain fees to the actual acquisition or disposal and count them once. If a fee is paid in a different cryptocurrency, that payment can create a separate disposal of the fee token. Do not deduct a fee from proceeds and again include it as an independent cash expense.

Futures, options and CFDs may have different K4 treatment depending on the underlying asset and contract. A close_long label proves only that the exchange realised a position; it does not determine the Swedish legal instrument or K4 section. Funding and contract settlement fees remain separate until exchange P&L is reconciled.

A genuine business activity follows business-income and accounting rules rather than the private 70% crypto-loss rule. High frequency alone is not enough. Keep the factual profile and consult the Sweden exchange-report guide when consolidating spot and derivatives.

Records that support a Swedish loss

• complete exchange and wallet history;
• asset, quantity, date, timestamp and transaction ID;
• SEK price source for each disposal and acquisition;
• average-cost pool before and after each event;
• fee asset and SEK value;
• own-wallet ownership evidence;
• separate gain and loss aggregation by token;
• K4 line reconciliation and retained source exports.

If a price or acquisition is missing, mark the result not computable and continue processing other verified transactions. A zero cost placeholder is not a confirmed Swedish omkostnadsbelopp.

Frequently asked questions

Official Swedish sources

• Skatteverket: cryptocurrency disposals, average cost, K4 and 70% losses
• Skatteverket: K4 examples for other assets and derivatives
• Skatteverket: official individual tax return service

Reviewed 1 September 2026. The report calculates supporting values; the final capital-tax result comes from the complete Swedish return.

Disclaimer: This article is for general informational purposes only and does not constitute tax advice. For individual tax advice, consult a licensed tax professional.