How to Classify Cryptocurrency Transactions According to the AEAT

Correctly classifying cryptocurrency transactions is one of the most important steps in the tax process. It determines whether a transaction generates a capital gain, an income, or a simple internal transfer with no tax impact.

An incorrect classification can alter your tax return and cause discrepancies with the AEAT. Therefore, it’s essential to apply the proper tax criteria to each type of transaction based on its nature and the applicable regulations.

Tax classification determines how each transaction is taxed and where it should be included in your tax return. Selling Bitcoin (capital gain) is not the same as earning staking rewards (investment income).

Impact on Your Tax Return

Each type of transaction has:

• Different tax rates: Capital gains are taxed under the savings base (19%–28%), while other types of income may have different treatment
• Different tax forms: Some are declared in Form 100, others may require additional information
• Different calculation methods: FIFO for capital gains, market valuation for income

An incorrect classification can lead to:

• Miscalculating the taxable base
• Applying incorrect tax rates
• Omitting transactions that must be declared
• Including movements with no fiscal impact

The Spanish Tax Agency (AEAT) mainly distinguishes three categories of cryptocurrency transactions:

1. Capital Transactions

Definition: Purchases, sales, or exchanges of cryptocurrencies that generate capital gains or losses.

Examples:

• Selling Bitcoin for euros
• Exchanging Ethereum for another cryptocurrency (swap)
• Using cryptocurrencies to purchase goods or services
• Token conversions on decentralized exchanges

Taxation:

• The FIFO method applies to determine acquisition cost
• Gains are taxed under the savings base (19%–28%)
• Losses can be offset against other capital gains

2. Investment Income (Rendimientos del Capital Mobiliario)

Definition: Income earned from staking, lending, or rewards from decentralized protocols.

Examples:

• Staking rewards from ETH, ADA, DOT, etc.
• Yield farming or liquidity provision rewards
• Income from crypto lending
• Airdrops received as rewards or incentives

Taxation:

• Valued at market price at the time of receipt
• Taxed as investment income
• Declared annually, even if not converted to euros

3. Non-Taxable Operations

Definition: Internal movements between wallets or transfers between your own accounts that have no tax implications as long as they can be properly justified.

Examples:

• Transferring Bitcoin from Binance to your hardware wallet
• Moving Ethereum from MetaMask to Ledger
• Consolidating funds into a single wallet
• Deposits and withdrawals on exchanges

Important:

These operations DO NOT create a taxable event, but they must be properly documented to avoid confusion with the AEAT. It’s crucial to prove they are internal movements, not sales or exchanges.

To classify each transaction correctly, the AEAT requires analyzing the economic purpose and outcome of the operation.

Key Questions to Classify a Transaction:

1. Does ownership of the asset change?

   • Yes → Probably a capital transaction
   • No → May be an internal movement

2. Is there any income or yield generated?

   • Yes → Could be investment income
   • No → Analyze whether it’s an exchange or transfer

3. Is there an economic exchange?

   • Yes → It’s a taxable exchange (swap)
   • No → Likely a non-taxable movement

4. Can you prove it’s an internal movement?

   • Yes (same ownership, controlled wallets) → Non-taxable
   • No → Must be treated as a capital transaction

Practical Example of Classification

Transaction: You move 1 ETH from Coinbase to Uniswap and exchange it for 2000 USDC.

Analysis:

1. First part (Coinbase → Uniswap):

   • Internal movement: You’re transferring funds between platforms you control
   • No tax impact

2. Second part (ETH → USDC on Uniswap):

   • Swap/exchange: You’re trading one asset for another
   • Generates a capital gain or loss
   • The gain/loss is calculated as the difference between the selling value of ETH and its acquisition cost

For example, a token swap on a DEX is a taxable exchange, whereas moving funds between personal wallets is not.

Information Needed for Proper Classification

The key is to have complete information:

• ✅ Exact dates of each transaction
• ✅ Market prices at the time of the operation
• ✅ Source and destination addresses (to identify internal transfers)
• ✅ Purpose of each transaction (buy, sell, swap, staking, etc.)
• ✅ Transaction hash for blockchain traceability
• ✅ Exchange or protocol where it occurred

Only with this can you ensure traceability and consistency in your tax report.

Error #1: Not Treating Swaps as Exchanges

One of the most frequent mistakes is treating crypto swaps as simple conversions with no tax implications, when in reality, they are taxable exchanges.

Correct: Each swap generates a gain or loss that must be calculated using FIFO.

Error #2: Failing to Declare Staking Rewards

Another common mistake is not declaring staking or airdrop rewards, assuming they are ‘unrealized’ until sold.

Correct: Staking rewards must be declared annually at their market value when received.

Error #3: Confusing Internal Movements with Sales

It’s also common to incorrectly classify internal transfers as real buy/sell operations.

Correct: Internal wallet transfers DO NOT create taxable events if you can prove you control both wallets.

Error #4: Not Applying FIFO Correctly

Many investors calculate capital gains incorrectly by not properly applying FIFO, leading to inaccurate results.

Correct: The first cryptocurrencies you bought are considered the first ones sold.

These errors can cause inconsistencies and alerts during AEAT reviews.

At Cleriontax, we analyze every transaction from both a technical and tax perspective. We combine advanced automation with manual review to identify the exact nature and tax impact of each operation.

Our Classification Process

1. Data import from exchanges, wallets, and blockchains
2. Initial automated analysis of each transaction
3. Identification of transaction type:
   • Buy/sell
   • Swap/exchange
   • Staking/lending
   • Internal movement
   • Airdrop/reward
4. Detection of internal movements through address analysis
5. Historical market price calculation
6. Manual review by specialized tax advisors
7. Cross-validation across data sources
8. Generation of a classified and verified tax report

Our system detects:

• ✅ Internal wallet transfers
• ✅ Token exchanges (swaps)
• ✅ Complex DeFi operations
• ✅ Passive income (staking, farming)
• ✅ Airdrops and rewards
• ✅ Transaction fees (gas fees)

By applying AEAT’s official criteria, we ensure each tax report is complete, consistent, and fully compliant.

The tax classification of crypto transactions requires precision and specialized expertise. Each mistake can lead to penalties or adjustments by the AEAT, so it’s crucial to work with verified reports and consistent methodologies.

Key points:

• Correctly identify the type of transaction (capital, income, or internal)
• Apply proper tax criteria according to AEAT regulations
• Maintain full traceability of all transactions
• Document internal movements properly
• Accurately calculate capital gains using FIFO

At Cleriontax, we transform thousands of transactions into structured, auditable data, ensuring every operation is properly classified and ready to declare with total confidence.

Don’t leave the classification of your crypto transactions to chance. Our team of experts ensures that every transaction is classified correctly according to AEAT criteria.

Request Your Tax Report → →

Contact our team for a free initial consultation. We’ll explain exactly how we classify your operations and why our reports are the most accurate in the market.

Disclaimer: This article is for informational and educational purposes only. It does not constitute personalized tax advice or investment recommendations. Tax regulations are subject to change, and each individual situation is unique. Always consult a certified tax advisor for your specific case.

Last updated: October 2025

Published by: Cleriontax Team – Experts in Cryptocurrency Taxation and Data Analysis