Nadia Benali, who is French-Moroccan, works as a designer in Málaga. On 31 December 2025 she held cryptocurrencies on two platforms whose custodian entities are outside Spain: on the first, 12 ether and 30,000 USDC; on the second, 400 units of SOL. In March 2025 she also closed a third account on another foreign platform, where she held bitcoin that she had already declared on her 721 for 2024. She knows she has to file Modelo 721, the Spanish return on virtual currencies held abroad, but when she opens the form she wonders what exactly each box means and where she gets the figures from. Let us take it step by step.
The basis: what article 42 quater requires
Modelo 721 gives effect to article 42 quater of the Reglamento General de Gestión e Inspección (Royal Decree 1065/2007, the regulations on tax management and inspection), introduced by Royal Decree 249/2023. That article lists the information to be given, and the form simply turns it into fields:
| What the article requires | How it is put into practice |
|---|---|
| Identification of the custodian | Name or company name, tax identification number in its country of residence if it has one, and address or website address |
| Identification of each type of virtual currency | One line per currency |
| Balance on 31 December | In units of that currency |
| Valuation in euros | At the price on 31 December, stating which price has been used |
| Capacity of the declarant | Holder, authorised person, beneficiary, person with power of disposal or beneficial owner |
| Balance on the date of ceasing | For anyone who stopped having any of those capacities during the year |
It is filed electronically on the website of the Agencia Tributaria, the Spanish tax agency, between 1 January and 31 March of the year following the one to which the information relates.
First step: check the threshold
The 721 is only compulsory if the joint balance of the virtual currencies held in custody abroad, valued in euros on 31 December, exceeds 50,000 €. For Nadia, with prices assumed for the example:
| Platform | Currency | Units | Price on 31-12 | Value |
|---|---|---|---|---|
| Platform 1 | ETH | 12 | 3,100 € | 37,200 € |
| Platform 1 | USDC | 30,000 | 0.96 € | 28,800 € |
| Platform 2 | SOL | 400 | 180 € | 72,000 € |
| Total | 138,000 € |
It exceeds the threshold, so Nadia declares all the currencies, including the stablecoins. If each platform were below 50,000 € on its own but together they exceeded it, she would also declare everything: the threshold looks at the whole.
Second step: the price and its source
The Regulations state that the valuation is made at the price on 31 December offered by the main trading platforms or price-tracking websites and, failing that, at a reasonable estimate of market value. And they require the price or value used to be stated.
In practice it is advisable to:
- choose a recognised source and use the same one for all the currencies;
- take the price in euros on 31 December, or convert from dollars at that day's exchange rate, keeping a record of the rate used;
- keep a dated screenshot or export of that price;
- for illiquid tokens with no reliable price, document how the value has been estimated.
Differences of a few euros between sources have no practical significance; what does matter is that the figure can be traced if anyone asks.
Third step: the currency that is no longer there
In March Nadia closed the account on the third platform. As those coins had been declared on the previous 721, the Regulations require her to file in any case and to report the balance on the date she ceased to be the holder. That line carries the date of ceasing and the balance in units and in euros on that date.
If those coins had never had to be declared (for example, because in 2024 the total did not exceed 50,000 €), there would be no need to report the closure.
If you hold the same currency on two platforms, they go in two separate records, each with its own custodian. And if you hold five currencies on one platform, that makes five records. Grouping them "by wallet" is the most common formatting error, and in an information return every item grouped wrongly counts.
If you use several platforms and are not sure whether all of them have their custodian outside Spain, you can list them in the Modelo 720 form and we will check, one by one, which entity provides the custody and where it is located.
How to tell whether the custodian is "abroad"
A platform can operate in Spain under its own brand and yet provide custody through an entity located in another country. The Regulations treat as located abroad the coins whose custodian is not obliged to file in Spain the balance return that the Spanish income tax act imposes on resident custodians. So what you need to look at is not the website or the language of the app, but the entity named in the terms of service as the custody provider.
What Modelos 172 and 173 are and why you do not file them
Royal Decree 249/2023 introduced, in addition to the obligation behind the 721, two others that are met not by the investor but by the entities:
| Form | Who files it | What it reports | Basis |
|---|---|---|---|
| 172 | Custodians resident in Spain or with a permanent establishment here | Their clients' virtual currency balances on 31 December | Art. 39 bis RD 1065/2007 |
| 173 | Those who provide exchange services, act as intermediaries or provide custody from Spain | Acquisitions, transfers, swaps and movements of currencies | Art. 39 ter RD 1065/2007 |
| 721 | The resident themselves | Balances held by custodians abroad | Art. 42 quater RD 1065/2007 |
The logic is complementary: what is held with Spanish custodians is reported by the custodian (172); what is held abroad is reported by you (721). And transactions that go through Spanish intermediaries are reported by the intermediary (173), which lets Hacienda, as the Spanish tax office is commonly known, check your income tax return against it afterwards.
What the 721 does not include
- Coins in wallets whose private keys you control yourself, with no custodian: they are not included. We explain this in do cryptocurrencies go in the 720 or somewhere else?.
- The year's gains and losses: the 721 reports balances, not transactions. Swaps between currencies and sales are declared in your IRPF (Spanish personal income tax) return.
- Listed products on cryptocurrencies bought through a broker: they are securities and go, where applicable, on the 720.
The following years
Once filed, the 721 only becomes compulsory again if the joint balance grows by more than 20,000 € over the one that determined the last return, or if you stop holding coins already declared. With cryptocurrencies, given their volatility, the 20,000 € rule is triggered far more easily than with a bank account: a market rise without buying anything can oblige you to file again. The guide to Modelo 721 for cryptocurrencies develops these rules with more examples.
Anyone who combines cryptocurrencies with accounts and securities outside Spain usually needs the 720 and the 721 at the same time; at Salama Tax we explain how we prepare them together and what information we ask for about each platform.