How to Declare Cryptocurrencies in the Income Tax Return in Spain (2025 tax year)

Cryptocurrency taxation is one of the most frequent inquiries we receive at IN DIEM Abogados. With increased oversight by the Tax Authority and the entry into force of new reporting obligations, correctly declaring your crypto transactions is no longer optional: it is essential to avoid penalties and requirements.

In this updated guide for the 2025 tax year (to be filed in 2026), we explain how to declare cryptocurrencies in Spain, which transactions are taxable, how to calculate your capital gains, and why having a professional crypto tax report can make the difference between an impeccable return and a problem with the Tax Authority.

1. Legal framework: how are cryptocurrencies taxed in Spain?

The Tax Authority considers cryptocurrencies as patrimonial assets, not as legal tender. This means that any transaction generating a change in value must be included in the income tax return as a capital gain or loss.

✔ When must you declare cryptocurrencies in the Income Tax Return?

You must declare if you have carried out any of the following transactions:

• Sale of cryptocurrencies for euros
• Exchanges between cryptocurrencies (BTC → ETH, for example)
• Purchase of goods or services paying with crypto
• Obtaining rewards (staking, farming, mining…)
• Salaries or services received in cryptocurrencies

Holding cryptocurrencies without trading does NOT generate an obligation to declare.

Why has Tax Authority oversight increased?

Through forms 172 and 173, exchanges and trading platforms operating in Spain are required to annually report to the Tax Authority regarding their users’ holdings and transactions, enabling the AEAT to automatically cross-reference your transactions with your IRPF.

Additionally, the European MiCA framework reinforces transparency in the crypto-asset market and requires crypto service providers to comply with much stricter registration and traceability standards.

2. Which cryptocurrency transactions are taxable in Spain?

Not all cryptocurrency transactions have the same tax implications. It is essential to understand when a taxable event is generated and when it is not. Below, we detail the main transactions that must be included in your income tax return:

1. Sale of cryptocurrencies for euros or other fiat currency

When you sell Bitcoin, Ethereum, or any other cryptocurrency in exchange for euros, a patrimonial transfer occurs.

The difference between what you paid to acquire them (acquisition value) and what you receive from their sale (transfer value) determines the capital gain or loss you must declare.

Example: you purchased 1 BTC for €20,000 in 2022 and sell it in 2024 for €35,000. Your capital gain is €15,000.

2. Crypto-to-crypto exchanges

This is one of the most frequent errors among taxpayers. According to the Tax Authority, exchanging one cryptocurrency for another constitutes a patrimonial transfer, even if you do not receive euros.

Example: if you purchased Bitcoin for €10,000 and exchange it for Ethereum when the Bitcoin is worth €15,000, you must declare a gain of €5,000, even though you have not converted anything to euros.

3. Staking and DeFi rewards

Staking consists of locking cryptocurrencies to participate in the validation of blockchain transactions and receive rewards. Fiscally, these rewards are considered income from movable capital or capital gains, depending on their nature.

If you receive new cryptocurrencies as a staking reward, the market value of those cryptocurrencies at the time of receipt constitutes income that must be taxed. Subsequently, when you sell or exchange those rewards, you will generate a new capital gain or loss.

4. Airdrops and forks

Airdrops are free distributions of tokens, generally for promotional purposes. When you receive an airdrop, the Tax Authority may consider it a capital gain based on the market value of the tokens received at the time of receipt.

Hard forks (when a blockchain splits creating a new cryptocurrency) have similar treatment: if you receive tokens from the new chain, their initial market value may constitute a capital gain.

5. Mining

If you are professionally engaged in cryptocurrency mining, the income may be considered income from economic activities, which implies registering as self-employed and maintaining specific accounting. If it is a sporadic activity, the cryptocurrencies obtained will be taxed as capital gains based on their market value at the time of obtaining them.

6. Payments and compensation in cryptocurrencies

If you receive your salary or any type of compensation in cryptocurrencies, this constitutes employment income that must be declared based on its value in euros at the time of receipt. Subsequently, when you sell or exchange those cryptocurrencies, you will generate a new capital gain or loss.

REMEMBER:

Simply purchasing cryptocurrencies and holding them in your wallet does not generate any obligation to declare in the IRPF. Only transfer transactions are taxable.

3. How to calculate capital gain or loss?

Spain applies the FIFO (First In, First Out) method: the first cryptocurrencies you purchased are the first considered sold.

Additionally:

• Purchase fees increase the acquisition value.
• Sale fees reduce the transfer value.
• You must consolidate all your transactions from all exchanges and wallets into a single tax pool.

4. Documentation required to correctly declare cryptocurrencies

Correct cryptocurrency declaration requires comprehensive documentation. Lack of documentation may be interpreted as concealment of assets. The Tax Authority requires the ability to justify:

1. Complete transaction history

You need a chronological record of all your transactions: purchases, sales, exchanges, transfers between wallets, staking rewards, airdrops received, etc. This history must include:

• Exact date and time of each transaction
• Type of transaction (purchase, sale, exchange, transfer)
• Amount of cryptocurrencies involved
• Unit and total price in euros at the time of the transaction
• Fees applied
• Platform or exchange used

2. CSV exports from exchanges

Most exchanges allow you to export your transaction history in CSV format. These exports are useful but have limitations: they do not always include all transactions (especially transfers between platforms), may have errors in euro conversions, and do not facilitate the application of the FIFO method when operating on multiple platforms.

3. Screenshots and receipts

For significant transactions or on platforms that do not offer complete exports, it is advisable to keep screenshots of transactions, email confirmations, and any other receipt that proves the transaction.

Screenshots must show date, time, and visible data to be valid.

4. Personal wallet records

If you use non-custodial wallets (such as MetaMask, Ledger, or similar), you must document all transactions made from those addresses. Blockchain analysis tools can help you reconstruct the complete history of an address, but they require technical knowledge.

5. Justification of the origin of funds

In case of inspection, the Tax Authority may request that you prove where the money used to purchase cryptocurrencies came from.

We show you examples of accepted documents:

• Payslips
• Bank savings
• Declared income
• Patrimonial sales
• Justified inheritances or donations

IMPORTANT:

Keep all documentation for at least 4 years.

5. What is a Crypto Tax Report and why is it key for the IRPF?

A Crypto Tax Report is a technical-legal document that analyzes and classifies all your crypto transactions in accordance with Spanish regulations.

Although technically there is no specific legal obligation to have a crypto tax report, it is highly recommended. We explain why:

What is it for?

• ✔ Guarantees regulatory compliance
• ✔ Provides support against Tax Authority requirements
• ✔ Allows you to legally optimize your taxation
• ✔ Provides legal certainty and peace of mind

While there are online tools that automatically generate tax reports from exchange APIs, these tools are useful for simple operations but have significant limitations in complex cases:

Limitations of automated reports

• Do not correctly identify the type of transaction
• Traceability failures
• Problems with FIFO on multiple platforms
• Do not detect errors, duplicates, or airdrops
• Do not include legal analysis

✔ Advantages of professional report

• Complete fiat–crypto–fiat traceability
• Reconstruction of movements
• Adapted tax analysis
• Risk identification
• Legal tax optimization
• Defense before the Tax Authority

6. Risks of not having a professional report

Incorrect declaration may result in:

• AEAT requirements
• Regularizations with surcharges of 5% to 20%
• Penalties of 50% to 150%
• Late payment interest
• Even risk of tax offense

The investment in a professional report is minimal compared to the risks.

At IN DIEM Abogados, in collaboration with Cryptoveritas 360, we prepare crypto tax reports with complete traceability and specialized legal analysis to guarantee regulatory compliance and your security before the Tax Authority.

At IN DIEM Abogados, we are a law firm specialized in cryptocurrency taxation and new technologies. Together with our technology partner Cryptoveritas 360, we offer a comprehensive service that combines technical, legal, and tax analysis.

Our services include:

✔ Complete Crypto Tax Reports: With detailed traceability, correct tax classification, and support before the Tax Authority.

✔ Advice for filing the 2025 Income Tax Return: We prepare and file your IRPF securely and optimally.

✔ Regularization of previous tax years: Complete reconstruction of complex histories, wallets, and movements.

✔ Defense against requirements or penalties: We respond to the Tax Authority on your behalf with all necessary legal documentation.

✔ Personalized attention by an expert lawyer: Direct contact 24/7 to resolve doubts and accompany you throughout the process.

✔ Maximum confidentiality and professionalism: Your information will be treated with absolute rigor.

If you operate with cryptocurrencies, we help you declare correctly and avoid risks.

Contact us. We are here to help you.

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Frequently Asked Questions (FAQs)

Cryptoveritas 360: our technology partner

Publications about Crypto on our blog

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Our multidisciplinary team also advises international companies—including Europe, Latin America, and Asia—that wish to establish or expand in Spain under the MiCA regulatory framework, whether by obtaining the CASP license from the CNMV or the incorporation of companies and compliance structures adapted to the European market.

Thanks to a hybrid work methodology (in-person and online), we guarantee the same level of quality, confidentiality, and efficiency for both local and foreign clients, supporting each project from initial planning to effective obtaining of regulatory authorization.

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