Modelo 720 and Modelo 721: Getting the Foreign Asset Filing Right

~17 min read

A guide for anyone who has become (or is about to become) a Spanish tax resident and needs to work out what foreign assets to declare, on which form, and by when - built around the edge cases people actually get wrong: authorised signatories on accounts, self-custody crypto wallets, retirement accounts like a 401(k) or IRA, and joint accounts held by spouses.

A practical guide for anyone who has become (or is about to become) a Spanish tax resident and needs to work out what foreign property has to be declared, on which form, and by when. Unlike most guides online, this one covers not just the official thresholds and deadlines but the edge cases people actually get wrong - authorised signatories on accounts, self-custody crypto wallets, retirement accounts like a 401(k) or IRA, and joint accounts held by spouses.

How to use this guide. It does not replace advice from a licensed asesor fiscal on your specific situation - every case has its own details (which countries the assets are in, how they are held, the year’s transaction history). This guide covers the preparation: what counts toward the return, how to calculate the thresholds, and where money is most often lost through error. Calculating the final figures and actually filing the returns (Modelo 720, Modelo 721, and later Renta and Patrimonio) is done by a licensed asesor fiscal.

Contents


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2. Who has to file

The duty falls on Spanish tax residents - individuals, legal entities, permanent establishments in Spain and, in certain cases, structures without separate legal personality (estates, trusts and similar arrangements). The key concept is not just “owner” in the narrow sense, but anyone who is:

That last category is the most underestimated, and it is exactly where people trip up who are certain that, since an asset “isn’t theirs,” there is nothing to declare.

2.1. Joint accounts and spouses

The official position (confirmed in AEAT’s own FAQ guidance on Modelo 720): a joint account is declared at its full balance, with no proportional split, alongside each co-holder’s percentage of ownership. Both co-holders, if both are Spanish tax residents, are required to file - each on their own return, stating the full amount plus their own share.

Separately - the marital community property regime (régimen de gananciales, common in a number of Spanish autonomous communities and recognised by default for spouses from certain civil-law jurisdictions): if an asset belongs to the couple’s joint property, both spouses are required to declare it, even if only one of them is the formal account or asset holder.

2.2. Authorised signatories (apoderados)

This is the single most common source of the “I thought that since I’m not the owner, I don’t need to declare” mistake. The official position on bank accounts is unambiguous: an authorised signatory (apoderado) on a foreign bank account has their own independent filing duty once the threshold is crossed, and it does not matter that the money in the account is not personally theirs. Only a specific statutory exemption (exoneración) removes this duty - not the fact that you are “merely authorised, not the owner.”

An important nuance: this authorised-signatory duty applies specifically to bank accounts (the category governed by Article 42 bis). For the other two categories - securities and real estate - an equivalent “authorised person” concept is not formally set out as broadly, but if you genuinely hold a right of disposal over the asset (power of attorney to manage a portfolio, power to sell a property), that case is worth assessing separately rather than assuming it works the same way as bank accounts.

This matters in particular if, for example, you have been added as an authorised signatory on a parent’s account, a business partner’s account, or the account of a company registered abroad - these situations are easy to overlook precisely because the money “isn’t yours.”

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3. Checklist by asset category

Modelo 720’s three categories are fully independent of each other: the €50,000 threshold is checked separately for each category, not on their combined total. If you have €40,000 in accounts and €40,000 in securities, as a general rule neither needs to be declared (provided neither category on its own crosses the threshold).

3.1. Bank accounts

Which exchange rate to use for the euro conversion

Foreign currency is converted to euros using the official rate published by the European Central Bank, for the date the balance refers to (usually 31 December). Using the exchange rate quoted by the bank the account is held at, or a random aggregator site, is not recommended - Hacienda checks against the ECB rate specifically, and a discrepancy can itself become a reason for questions.

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3.2. Securities, ownership stakes, life insurance

Life insurance: there is an exception. If the insurer itself (through its representative in Spain) already reports this policy regularly to Hacienda, the policyholder does not have a separate duty to declare it on Modelo 720. This exception should be checked individually against the specific product and country, rather than assumed by default just because “it’s insurance” - it only works if the insurer’s own reciprocal reporting condition is actually met.

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3.3. Foreign real estate

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3.4. Retirement and savings accounts: 401(k), IRA and similar products

This is one of the most underestimated grey areas - and also one of the costliest to get wrong, because balances in retirement accounts are often substantial.

The general exclusion rule: rights under a foreign pension plan are not included in Modelo 720 if the plan’s structure matches the Spanish concept of a pension scheme - meaning a payout is possible only on one of a specific set of triggers (retirement, death, loss of the breadwinner, orphanhood or disability), and the holder cannot access contributions before one of those events occurs.

The problem is that many products marketed as “retirement” products in their home country do not, in practice, satisfy this strict test - because they allow broader access to funds than the Spanish rule permits. Each product needs its own analysis, not a decision based on its name:

Why the product's name alone is not enough to rely on

The Spanish rule looks not at a product’s marketing name (“retirement account,” “savings plan”) but at its legal structure: whether access to funds is genuinely closed off until a strictly defined set of events. A product with more flexible withdrawal terms (for example, allowing early withdrawal with a penalty rather than an outright block) risks falling outside the exclusion - in which case it needs to be declared as an ordinary asset in the relevant category (most often as securities or as an account, depending on the product’s structure). This is worth working through with an asesor fiscal against your plan’s actual terms, not by analogy with someone else’s “similar-looking” account.

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3.5. Crypto-assets: Modelo 721

Crypto is declared separately from Modelo 720, on Modelo 721, and it has its own threshold logic and rules.

The key distinction: custodial versus self-custody. Hacienda’s official position: crypto held in a wallet where you personally control the private keys, and it is not held in custody by a third party or custody-service provider, is not subject to declaration on Modelo 721. This covers classic hardware wallets and most cold wallets in the strict sense.

The flip side: crypto on foreign exchanges and platforms that hold the private keys on your behalf is subject to declaration once its value as of 31 December exceeds €50,000.

The risk of getting it wrong in either direction

It is easy to make either mistake here. The first is declaring a self-custody wallet that did not need declaring (an unnecessary, but not risky, error). The second, far riskier, mistake is deciding that “since it’s my own wallet on an exchange” it needs no declaration, when in fact the exchange holds your keys (meaning it is custodial) - in which case the duty applies. Before drawing a conclusion, explicitly check the specific platform’s architecture, rather than relying on a general sense of “I control everything myself.”

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4. Thresholds and when to refile

An initial filing is required if at least one category (accounts / securities / real estate, and separately, crypto under Modelo 721) exceeds €50,000 as of 31 December.

After the first filing, refiling in later years is not automatic every year - it is only required when one of these events occurs:

An important practical point people often miss: closing or selling an asset is itself an event that requires a new return, not a reason to stop thinking about the duty. Many wrongly assume that once the asset is gone, there is nothing left to report - but the rule specifically requires reporting that disposal, not staying silent about it.

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5. Filing deadlines

Both returns are filed in the same window: 1 January to 31 March of the year following the tax year. For example, for assets as of 31 December 2026, filing runs from 1 January to 31 March 2027.

It makes sense to start gathering data well ahead of time, not in the final days of March - translating statements, confirming exchange rates, checking joint accounts and authorised signatories all take time, especially if assets are spread across several countries and jurisdictions.

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6. Penalties: what changed after 2022, and how to avoid them

Before 2022, the Modelo 720 penalty regime was exceptional and disproportionately harsh: fixed fines from €5,000 per item with a €10,000 minimum, and undeclared assets could be reclassified as unjustified capital gains with no statute of limitations. On 27 January 2022, the EU Court (case C-788/19) found this regime disproportionate and contrary to the free movement of capital. Law 5/2022 brought penalties into line with the general regime.

The current penalty regime (the general rules under Spain’s General Tax Law, LGT, rather than a special regime):

The filing duty itself has not gone away - only the size of the penalty for breaching it has changed. Do not confuse “penalties got softer” with “the return became optional.”

Why a review can arrive years later, not right away

In practice, Hacienda does not always react immediately to a data mismatch. It often waits, closer to the end of the general statute of limitations (usually 4 years), before opening a review - at which point the claim covers several periods at once rather than a single year. This is not a reason to relax just because there was no immediate reaction: the sooner past periods are put in order (including through a voluntary late filing and the associated 50% discount), the smaller the accumulated risk.

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7. Common mistakes

What most often goes wrong
  1. “I’m not the owner, just authorised - so I don’t need to declare.” Wrong for bank accounts: an authorised signatory has their own independent filing duty once the threshold is crossed (see section 2.2).
  2. Declaring a share instead of the full amount on a joint account. Joint accounts are declared at the full balance with your percentage stated separately, not a proportional share (see section 2.1).
  3. Mixing up Modelo 720 and Modelo 721. Crypto is not covered by any of Modelo 720’s three categories - it has its own form and its own custodial/self-custody analysis.
  4. Not reporting a closed account or a sold asset. Disposing of a previously declared asset itself requires a new filing - staying silent does not remove the duty (see section 4).
  5. Assuming a retirement account is automatically excluded just because of its name. A 401(k), IRA and similar products need an individual check of their access conditions, not a blanket “it’s a pension, so it’s fine” assumption (see section 3.4).
  6. Not checking a crypto platform’s architecture. Custodial holdings on a foreign exchange are declared, self-custody of your own private keys is not - the mistake can go either way (see section 3.5).
  7. Using an unofficial exchange rate instead of the ECB rate for the reporting date - a discrepancy surfaces easily during a review.
  8. Not cross-checking Modelo 720/721 data against later returns - the income tax return (Modelo 100) and, above the threshold, wealth tax (Modelo 714/718). A mismatch between what is declared on different forms is a typical trigger for a review.
  9. Overlooking life insurance policies with a savings component, without checking whether the exception through the insurer’s own reporting applies.
  10. Leaving data preparation until the last days of March, especially with assets in several countries and jurisdictions - gathering and reconciling everything in a few days is objectively harder than starting a month or two ahead.

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8. What happens after filing

Modelo 720 and Modelo 721 are informational returns - filing them does not by itself create an immediate tax bill. But the data becomes part of the overall picture Hacienda cross-checks against the income tax return (Modelo 100) and, above €2,000,000 in gross assets, the wealth tax return (Modelo 714), and above €3,000,000 in net worth, the tax on large fortunes (Modelo 718). That is exactly why the data across all these forms needs to be consistent with each other, not just formally filed separately.

If an error in an already-filed return turns up afterward, it can (and should) be corrected through a supplementary return (complementaria) before Hacienda finds it - this generally allows you to avoid a penalty, paying only the additional tax owed, if any.

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Frequently asked questions

What is the difference between Modelo 720 and Modelo 721?

Modelo 720 is the return for foreign assets across three independent categories (bank accounts, securities and ownership stakes, real estate), in place since 2013. Modelo 721 is a separate return specifically for foreign crypto-assets, introduced later (in force from the 2023 filing year) and does not fall under any of the Modelo 720 categories.

Do I need to declare an account I only have power of attorney over?

Yes. For bank accounts, an authorised signatory (apoderado) has their own independent filing duty once the threshold is crossed - the fact that the funds are not yours does not by itself remove the obligation.

Do I need to declare crypto held in a cold wallet?

No, as long as you control the private keys yourself and the wallet is not held in custody by an exchange or other institution. Crypto on foreign exchanges that hold the keys on your behalf is declared on Modelo 721 once it crosses the €50,000 threshold.

What happens if I sold or closed a previously declared asset?

Disposing of an asset is itself an event that requires a new filing - it is not a reason to stop reporting. On top of that, a refiling is also required if a category's value rose by more than €20,000 compared with your last filed return.