The question is being asked more and more often by investors, self-employed professionals and companies that operate with cryptocurrencies. If you hold cryptocurrencies, it is normal to wonder how far the Spanish Tax Agency can go. Can they freeze your wallet? Seize your bitcoins? Access your private keys?

The answer is not as simple as yes or no. And that is precisely why many taxpayers make mistakes that worsen their tax situation.

In this article, we explain what the Spanish Tax Agency can actually do, what it cannot do, and when you should act before the problem escalates.

What is an administrative seizure and how does the Spanish Tax Agency act?

A seizure is a coercive measure that allows the Spanish Tax Agency to withhold or intervene in a taxpayer’s assets in order to collect a tax debt that is liquid, due, enforceable, and properly notified to the taxpayer.

There is an administrative procedure that must be followed, regulated by the General Tax Law and the General Collection Regulations.

Once the procedure has started, the Spanish Tax Agency issues an enforcement order (the formal notice that your assets will be seized if you do not pay).

What can be seized?

• Bank accounts
• Wages and receivables
• Movable and immovable property
• Property rights

Practically any asset or right with economic value. The key is to understand how cryptoassets fit into this framework.

Key difference: bank account vs. cryptocurrency wallet

Many people equate the two, but they are not the same for seizure purposes.

When the Spanish Tax Agency seizes a bank account, it simply sends an order to the bank. The bank is obliged to withhold the available balance and transfer it to the Administration. It is a technical, fast and effective procedure.

However, a self-custodied wallet (non-custodial wallet) does not work that way. There is no intermediary. There is no bank. There is no entity the Spanish Tax Agency can order to do anything. Your private keys are in your possession, and without them, no one can move the funds.

This means that the Spanish Tax Agency cannot directly “freeze” a decentralised wallet, because technically it has no way to access it. It cannot freeze your bitcoins on a Ledger, a Trezor, or any wallet you control without intermediaries.

However, that does not mean you are safe.

Can the Spanish Tax Agency indirectly intervene in your cryptocurrencies?

Yes. And in several ways.

1. Seizures on centralised exchanges

If you hold cryptocurrencies on platforms such as Binance, Coinbase, Kraken or any centralised exchange, you are using a custody service. In other words, they hold your private keys.

In that case, the Spanish Tax Agency can approach the exchange directly and order the freezing or seizure of your balances. And the exchange is obliged to comply, just like a bank.

This means that:

• The Spanish Tax Agency can know what you hold on exchanges
• It can request detailed information about your transactions
• And it can seize those funds if there is a debt

This duty to cooperate is reinforced by European regulations and the new tax information exchange mechanisms (DAC7 and DAC8), as we have analysed in other IN DIEM blog articles on cryptocurrency taxation and reporting obligations.

2. Information requests and compelled cooperation

Even if the Spanish Tax Agency cannot access your self-custodied wallet, it can require you to provide information about it during an audit. And if you refuse, the consequences can be serious.

Refusal to cooperate may result in:

• Penalties for obstruction (up to €150,000 depending on severity)
• A presumption of concealment, which may lead to a tax crime if the evaded tax exceeds €120,000
• Ex officio assessments that almost always harm the taxpayer

In addition, if the Spanish Tax Agency considers that you have deliberately concealed assets or income, it may initiate criminal proceedings. And in that context, a judge could order you to hand over your private keys or disclose your balances, under threat of criminal liability.

3. Seizure of other assets to cover the debt

If the Spanish Tax Agency cannot reach your cryptocurrencies directly, it will go after what it can seize: your salary, your bank account, your car, your home.

It is a mistake to think that because your funds are in crypto, you are protected from seizure. All you achieve is that the Spanish Tax Agency attacks other fronts, often more aggressively.

What role do exchanges play in all this?

In recent years, platforms such as Coinbase, Binance, Kraken and others have ceased to be tax grey areas. They are now regulated entities that must comply with KYC (Know Your Customer) and AML (Anti-Money Laundering) rules, and are required to cooperate with the tax authorities.

According to the Ministry of Finance, cryptoasset service providers must report transactions above certain thresholds and are required to respond to information requests from the Spanish Tax Agency.

This means that:

• The Spanish Tax Agency can ask an exchange for all your activity on the platform
• It can order your funds to be frozen in the event of a seizure
• It can automatically receive information about your transactions if Spain and the exchange’s country have information exchange agreements

It is not a matter of willingness, but of regulatory compliance. The CNMV and the European cryptoasset supervisory framework (MiCA) are moving in this direction.

As we explain in our articles on Spanish Tax Agency audits and crypto, data matching is now far more effective than it was a few years ago.

Common mistakes that make the problem worse

Thanks to our extensive experience in crypto taxation, we can summarise what we have seen.

Many taxpayers, whether due to lack of knowledge or poor advice, have made decisions that have worsened their situation:

• Ignoring notifications from the Spanish Tax Agency. Many think that if they do not respond, the problem will go away. It is exactly the opposite: it triggers enforcement proceedings.
• Transferring crypto to “anonymous” wallets during an audit. This may be interpreted as concealment of assets, turning an administrative infringement into a potential tax crime.
• Relying on advisers who do not understand crypto. A generalist accountant may not be up to date with the tax specifics of cryptoassets, and that can be very costly.
• Not voluntarily regularising in time. If you have undeclared income, it is better to opt for voluntary regularisation before the audit arrives. Penalties are much lower.

Why do you need an expert lawyer like IN DIEM?

Because when the Spanish Tax Agency detects cryptocurrency transactions, you are not facing a standard tax issue. You are facing a scenario where technology, tax rules and administrative law intersect in a complex way.

And this is where most tax advisers get lost.

A generalist adviser may be excellent at handling personal income tax, corporate tax or traditional VAT. But cryptocurrencies are different: blockchain traceability, self-custodied wallets, foreign exchanges, European regulations such as DAC7 and DAC8, staking taxation, DeFi, NFTs… It is not their field.

And worst of all, when they improvise, mistakes become very expensive.

What really makes the difference

It is not enough to know tax. You need to know tax defence.

When the Spanish Tax Agency comes after you, you need someone who:

• Understands how the AEAT traces transactions on the blockchain
• Knows what information they can (and cannot) request
• Knows the deadlines, procedures and available appeals
• Has real experience defending taxpayers in crypto audits
• Knows when to negotiate, when to appeal and when to regularise voluntarily

That is exactly what IN DIEM Abogados does.

How can we help you?

We specialise in cryptoasset taxation and tax defence. At IN DIEM Abogados, we are a law firm specialising 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.

Contact us. We are here to help you.

We work with taxpayers who:

• Have received an information request from the Spanish Tax Agency about cryptocurrency transactions and do not know how to respond without worsening their situation.
• Have undeclared cryptoassets and need to regularise strategically, minimising penalties and preventing the issue from escalating into a tax crime.
• Have been notified of a seizure or enforcement order related to crypto income. Time is running out, and every day counts.
• Are being audited because the Agency has detected suspicious transfers to/from exchanges or wallets. We defend your interests at every stage.
• Trade cryptocurrencies regularly and want to plan their tax position proactively, before problems arise. Prevention is always cheaper than defence.
• Made tax mistakes in previous years and need to correct them before the Spanish Tax Agency discovers them. We design regularisation strategies that minimise the impact.

Why IN DIEM is different?

We are not a generalist firm that added “crypto” to its business card.

We are tax lawyers specialising in cryptoassets and tax defence. We understand blockchain technology, know the regulations in detail and, above all, know exactly how the Spanish Tax Agency acts when it detects cryptocurrency transactions.

That experience makes the difference between an effective defence and improvisation that ends in avoidable penalties.

Do not wait for the problem to grow

If you hold cryptocurrencies and any of these situations sounds familiar, the time to act is now. Every day that passes without specialised advice can worsen your position vis-à-vis the Spanish Tax Agency.

Contact IN DIEM Abogados. The first consultation may be the decision that makes the difference between resolving the problem or watching it escalate until it is too late.

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At IN DIEM Abogados and Cryptoveritas 360 we provide our services at all our offices and locations in Spain, offering direct and personalized coverage in Madrid, Seville, Málaga, Marbella, Las Palmas de Gran Canaria, as well as continuous service through our digital channels for clients throughout the country.

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 through obtaining the CASP license from the CNMV or the incorporation of companies and compliance structures adapted to the European market.

Thanks to a hybrid working 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 regulatory authorization.

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We offer our clients the option of being assisted via video call or videoconference, as well as by telephone, according to our clients’ preference, so that the assistance is as personal as possible, with absolute immediacy, without the need to travel. This service is complemented by communication via email, which facilitates the analysis and delivery of documentation.

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For more information on the Online Legal Advisory Service HERE, the 24-hour and Urgent Service, HERE, and some recognitions, we leave you this link.

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