ICOs, IEOs and STOs: taxation and tax implications in Spain

Initial Token Offerings (ICOs), Exchange Offerings (IEOs) and Security Token Offerings (STOs) are financing mechanisms specific to the blockchain ecosystem. They had their peak in 2017-2018 and are still relevant. Its taxation has specific nuances.

What is an ICO?

An ICO is a public sale of tokens by a crypto project to finance itself. Investors send BTC or ETH and receive tokens from the new project at a certain price.

Historical example: In the Ethereum ICO (2014), investors sent Bitcoin and received ETH at ~$0.31/ETH.

Taxation of the investor in an ICO

By participating in the ICO:

• You send BTC/ETH → transmission of BTC/ETH. Capital gain/loss with respect to your cost of acquiring BTC/ETH.
• You receive tokens from the new project → you receive them at the ICO price (that is your acquisition cost).

Example:

• I bought 1 ETH for €200.
• In the ICO I send 1 ETH (current price €300) and receive 1,000 TOKEN at €0.30.
• ETH transmission: €300 − €200 = €100 capital gain (savings base).
• Cost of acquiring 1,000 TOKEN: €300 (price of ETH at the time of the ICO).

When selling the tokens:

• Sale price − €0.30/token = profit/loss.

IEO (Initial Exchange Offering)

The IEO is the same as the ICO but managed by an exchange (Binance Launchpad, Coinbase, etc.). The exchange does the KYC and sells the tokens on its platform.

Taxation: Exactly the same as the ICO. If you pay with BNB/ETH → transmission. You receive tokens → acquisition cost at the IEO price.

The problem of failed ICOs or scams

Frequent situation: You participate in an ICO, you receive tokens that are never listed or that are listed and drop to 0, and the project disappears.

Can you deduct the loss?

• Only if there is transmission. If the tokens are worth 0 but you can't sell them (no market), there is no transmission → no deductible loss yet.
• If the project was a proven fraud (scam): Same problem as bankruptcies. Pending firm criteria.
• Tip: Some tokens from failed ICOs continue to trade on DEXs with very low prices. You can sell them and realize the loss.

STOs (Security Token Offerings)

STOs issue tokens that represent securities (shares, bonds, shares). Unlike utility token ICOs, STOs are regulated as securities.

Taxation of STOs:

• Returns on the underlying asset (dividends if it represents shares → capital; interest if it represents bonds → capital).
• Gain/loss when transmitting → savings base.
• They are fiscally closer to listed shares.

Governance tokens received retroactively

Very common in DeFi: retroactive token drops to users who used the protocol before there was a token. Example:

• Uniswap distributed UNI in September 2020 to all historical users.
• 400 UNI per wallet that had used Uniswap before the snapshot.

Taxation: Capital gain upon receipt. Retroactive token distributions are airdrops → general income tax basis.

If the token then rises → second capital gain based on savings when selling.

Blocking and vesting in ICOs

Many ICOs have vesting periods: tokens are distributed gradually over 1-3 years.

• The taxable event is when you receive the tokens (they are unlocked), not when you participate in the ICO.
• At the time of each unlock → market price of the token at that time.

Listing: when to declare "market value"?

A common problem: you participate in an ICO at the pre-sale price (€0.05/token), the token is listed at €2. Is there an income at the time of listing?

• No: The taxable event is the transmission, not the contribution. If you don't sell, there is no taxable income.
• The difference between the ICO price and the list price is not income until you stream.

Updated: April 2026 | Fiscal year: 2025