Modelo 720 and crypto: the tax limbo nobody explains

Modelo 720 and crypto: the tax limbo the Spanish tax authority won't clarify

Holding more than 50,000 euros in cryptocurrencies stored on a foreign exchange means, in theory, filing the Modelo 720, Spain's informational declaration of assets and rights located outside the country. In practice, the debate remains open: there is no official ruling on whether crypto counts as "assets abroad," whether a hardware wallet is "outside" Spain, or whether the tax authority can cross-check data with platforms that do not even operate under European supervision. The debate, open since late 2017, still has no official answer.

What is the Modelo 720 and why does it generate so much resentment

The Modelo 720 is an informational declaration: you pay nothing for filing it, but omitting it or filing late can trigger penalties that, in the original wording, reached 150% of the undeclared amount. That disproportion —a fine larger than the hidden assets themselves— is what has turned the rule into a symbol of what many consider a abusa of the free movement of capital within the EU. Some argue the penalty regime was struck down by European bodies; others point out that the reporting obligation remains in force and that, until there is a final ruling or a legislative change, the risk persists.

The obligation kicks in when the combined balance of accounts, securities or receivables held abroad exceeds 50,000 euros as of 31 December. And here the maze begins: if the assets grow by more than 20,000 euros compared with the previous year, you must file again. With crypto volatility, that threshold is crossed with a ease that borders on the absurd.

Does a wallet count as an asset abroad?

The key question has no official answer. A hardware wallet kept at home is not "in" any country: the keys controlling the funds exist in a distributed database, with no jurisdiction. Those who defend this interpretation argue that, if no foreign entity is custodying the balance, there is nothing to declare on the 720. The problem arises when those funds are moved to an exchange to convert them into euros: the tax authority only sees a transfer from a foreign platform to a Spanish account. The traceability is broken, and with it the alibi.

Some outright claim the tax authority has no technical means of knowing what is held on a foreign exchange or a PayPal account. That opacity, however, clashes with the Automatic Exchange of Information (AEOI), the international framework that obliges banks —and, under some readings, exchanges as well— to share data with tax authorities. The question of whether crypto platforms fall under that exchange remains unresolved.

Is every trade taxable, or only when converting to euros?

This is the point that generates the most tension. One school of tax advisers holds that every exchange between cryptocurrencies constitutes a barter: you swap bitcoin for ether, you alter your assets and therefore generate a capital gain or loss that must be declared on the IRPF (Spain's personal income tax), even if you never touched a euro. It is the same logic applied to a share swap. Taken to the extreme, anyone who has made hundreds of trades between altcoins would have to reconstruct the euro value of each one, with the exact price of the day and of the specific exchange.

The other, more pragmatic school argues that tax is only due when there is a conversion into fiat currency. They argue there is no specific legislation on crypto-to-crypto trading and that the tax authority, lacking data, is accepting declarations based on the flow of euros to and from the bank. A full calculation, trade by trade, is materially unviable for an individual with intense activity: some claim to have made tens of millions of trades spread across more than a dozen platforms.

The voluntary wealth declaration route

Faced with the uncertainty, some propose a defensive strategy: filing the wealth tax voluntarily —even though it is only mandatory above 700,000 euros— adding a note declaring the intention to hide nothing. The goal is not to pay, but to protect oneself against a future inspection: if the tax authority verifies that you always acted transparently, the accusation of concealment loses force. When the time comes to liquidate, the gain will be recorded as a capital increase.

The underlying problem is that there is no clear-cut law. Everything is assumptions, advisers' interpretations and binding consultations that refer to currencies, not cryptocurrencies. Until the BOE (Spain's official gazette) publishes a specific rule and an official spokesperson explains how it applies, every taxpayer navigates blind. And the antiestéticar of retroactivity —like the one that once caught sports bettors off guard— hangs over every decision.

The question left hanging is not how to declare, but whether the system is designed so that anyone can do it right. With the available data, the answer remains the same as years ago: nobody knows.