Buying and selling cryptocurrencies might seem like an activity outside the traditional tax system, but in Spain they're fully subject to taxation, with obligations that many holders are unaware of or underestimate until they receive a notice from the tax authorities.
When a capital gain is triggered with cryptocurrencies
As with any other asset, a capital gain or loss is triggered when you sell or exchange a cryptocurrency for a value higher or lower than what you paid for it. This includes not just selling for fiat money (euros), but also exchanging one cryptocurrency for a different one, which the tax authorities also treat as a taxable transaction, not a neutral "conversion."
Simply buying crypto doesn't trigger taxation
Buying cryptocurrencies with euros and holding them without selling or exchanging them doesn't, by itself, create any obligation to pay tax on a capital gain: taxation occurs at the moment of sale or exchange, not merely from holding the asset or from an unrealized increase in value.
How the gain is taxed: the savings tax base
Gains from cryptocurrencies are taxed within the savings tax base, under the same progressive scale applied to other capital gains (from selling shares, funds, or property), and in the same way, they can be offset against capital losses from other transactions, within the limits and timeframes set by the rules.
Using cryptocurrency to pay for things also triggers taxation
Something many people don't realize: if you use cryptocurrency to pay for a good or service directly (without first converting it to euros), the tax authorities consider that a disposal of that cryptocurrency has occurred at its market value at the moment of payment, triggering the corresponding gain or loss relative to your original acquisition price.
Reporting obligations for cryptocurrency held abroad
If you hold cryptocurrencies custodied on platforms or exchanges based outside Spain, and their value exceeds certain thresholds, you may be required to report them on specific informational tax forms, similar in spirit to the Modelo 720 for assets held abroad, though with its own dedicated form for digital assets. Failing to comply with these reporting obligations can carry significant penalties, regardless of whether the transaction itself produced a gain.
The importance of keeping a detailed record
Since many cryptocurrency transactions take place across different platforms, with multiple purchases at different prices over time, keeping an organized record of every transaction (date, amount, purchase and sale price) is essential for correctly calculating gains and losses when tax season arrives, avoiding the need to reconstruct your entire history at the last minute.
Before investing, understand the risk too, not just the tax treatment
Beyond taxation, cryptocurrencies are assets with considerably higher volatility than traditional investments. Our compound interest calculator can help you compare return scenarios as a rough guide, though it's worth remembering that no mathematical projection reflects the real risk of such a volatile asset.