Common spot trades, where you buy or sell cryptocurrency with speculation in mind, are taxed according to the State Taxation Act. Note that this is the case when selling crypto both for fiat currency and for other crypto. .
Profits from such spot trades must be declared as part of your personal income (box 20 on your annual statement in 2023). The tax rate depends on your other income but is taxed at up to approximately 53% (if you pay top-bracket tax).
Losses from spot trades must be declared as a tax deduction for common expenses (box 58 on your annual statement in 2023). The tax value of the deduction is approximately 27%.
In practice, the calculation of profits and losses is done according to the FIFO principle (First In, First Out) and when a sale occurs (upon realization of gains or losses).
This means that if, for example, you have bought 1.5 BTC in three trades where you bought 0.5 BTC each time, the profit from the sale of 0.25 BTC must be calculated by offsetting the purchase price for the first 0.25 BTC you bought against the sum you received for selling 0.25 BTC. This method must be used, even if you paid a much higher price for the last purchased 0.5 BTC and would therefore prefer to offset this purchase price against the sale price to calculate the profit.
In special cases, the tax authorities recognize that the calculation is made separately according to the asset-for-asset principle, and not according to the FIFO principle, if it can be documented that several quantities of the same cryptocurrency are kept separate. But it is a very special exception, and the authorities’ documentation requirements are very high. In practice, almost all trades are calculated according to the FIFO principle.
This may seem unreasonable. It is due to the generic nature of crypto. Until we get new tax rules on crypto, we expect the FIFO principle to be the predominant calculation method in practice. However, calculation on NFT trades follow an asset-for-asset principle because of the unique nature of NFTs.
Fees must be added to the acquisition cost when buying crypto and deducted from the selling price when selling crypto.
For example, if you buy 1 ETH for 15,000 DKK and pay 0.01 ETH in fees for the transaction (worth 150 DKK), the acquisition cost for your 1 ETH is 15,150 DKK.