Hard forks: how to declare the new tokens received
Hard forks —divisions of a blockchain that generate a new chain and new tokens— have been one of the most frequent events in crypto history. Bitcoin Cash in 2017, Bitcoin Gold, Ethereum Classic… How does Hacienda treat them?
What is a hard fork?
A hard fork occurs when a cryptocurrency community splits and creates two incompatible chains. Holders of the original currency receive tokens on the new chain in the same proportion.
Example: If you held 1 BTC when the Bitcoin Cash fork occurred in August 2017, you also received 1 BCH.
Tax treatment in Spain
The DGT has not issued a specific binding consultation on hard forks, but applying general principles:
At the time of the fork
Tokens received in a hard fork are treated similarly to a free airdrop: they are a capital gain not derived from a transfer, integrated into the IRPF general base (marginal rate).
The problem: At the exact moment of the fork, many tokens do not have an established market price. The most widespread conservative stance is:
- Value = 0 € if there is no liquid market at the time of the fork.
- Acquisition cost = 0 €.
- When sold → the entire sale price is a capital gain.
If there is a market price from the very beginning (listing on exchanges from day 1), that price is used.
When selling the forked tokens
Whatever the acquisition cost assigned at the fork, the subsequent sale generates a capital gain or loss in the savings base, calculated as:
Gain = Sale price − Acquisition cost assigned at the fork
The original token's cost does not change
The hard fork does not alter the acquisition cost of the original coins. If you held 1 BTC at 8,000 € and receive 1 BCH, the cost of your BTC remains 8,000 €. The BCH has its own cost (0 € or market price at the fork).
Soft forks
Soft forks that do not generate new tokens (only update the protocol) have no tax implications for the user.
Relevant historical examples
| Fork | Year | New currency |
|---|---|---|
| Bitcoin Cash | 2017 | BCH |
| Bitcoin Gold | 2017 | BTG |
| Ethereum Classic | 2016 | ETC |
| Bitcoin SV | 2018 | BSV |
Conclusion
Hard forks generate tokens that must be declared in the year of the fork. If there was no liquid market, a cost of 0 can be assigned and the entire gain declared when they are sold. Documenting the date and circumstances of the fork is essential to justify the acquisition cost to the AEAT.