The start of the tax season marks a particularly important moment each year for taxpayers and tax professionals. In Spain, the filing period for Personal Income Tax (IRPF) returns for the 2025 tax year opened on April 8, 2026, with a final deadline of June 30. In the Principality of Andorra, the tax calendar for the same year runs from April 1 to September 30, 2026. In this context, and coinciding with the start of both tax seasons, one of the most technically complex and interpretively uncertain issues currently on the subject takes center stage: the taxation of crypto assets.
The tax reporting of crypto assets has become a major challenge for investors, advisors, and tax authorities. What initially seemed like a simple obligation to declare capital gains and losses now requires a technical, tax, and documentary reconstruction of transactions carried out over years on exchanges, private wallets, decentralized protocols, and various blockchain networks.
In Spain, the Tax Agency stipulates that capital gains or losses derived from the transfer or exchange of virtual currencies must be included in Personal Income Tax (IRPF), whether they are exchanged for fiat currency or for other cryptocurrencies. Furthermore, each transaction must be calculated independently, and exchanges between different crypto assets are classified as swaps. This presents a clear practical challenge. Many investors have not operated solely on a centralized platform but have used multiple exchanges, non-custodial wallets, decentralized applications, network bridges, liquidity pools, staking protocols, or have engaged in direct buying and selling. In these cases, tax information is not always available in a single downloadable historical record but is instead scattered across CSV files, incomplete statements, on-chain logs, and public explorers for each cryptocurrency network.
Abast Legal is an international professional firm based in Andorra and Barcelona, specializing in tax advice, corporate law, and relocation services. With teams dedicated to international taxation, digital assets, and corporate transactions, the firm provides advice on Spanish, Andorran, and cross-border tax law to both individuals and legal entities. At the firm, we have observed that one of the most common mistakes regarding crypto assets is believing that filing a tax return simply involves downloading a report from an exchange. In practice, when an investor has traded on different platforms, wallets, or blockchain networks, it is essential to reconstruct the complete traceability of transactions to accurately calculate gains and losses. The challenge is compounded when there are past transactions, defunct exchanges, changes in tax residency, or transfers between personal and corporate accounts. In these cases, the problem is not only fiscal, but also evidentiary: it is necessary to be able to prove the origin of the funds, the cost of acquiring the assets, the transfer value and the documentation that supports each calculation.
In Spain, this scenario unfolds within a context of increasing transparency. Form 721 requires the annual declaration of virtual currency balances held abroad, due between January and March, while Forms 172 and 173 reinforce the flow of information to the Tax Authorities regarding cryptocurrency balances and transactions. In Andorra, however, there are currently no equivalent reporting requirements for crypto assets. Therefore, the comparison must be made from two perspectives: firstly, the lower formal burden in Andorra compared to the Spanish system; and secondly, the tax treatment provided for in the Principality’s regulations. In this regard, Law 24/2022 introduces a reduction clause applicable to certain digital assets, which can allow for a progressive decrease in taxation depending on the holding period, reaching virtually 0% effective taxation after five years, provided that the legal requirements are met. Therefore, in both Spain and Andorra, the tax analysis of crypto assets requires a methodology that combines tax knowledge, technical understanding of blockchain, and documentation skills. It is not enough to know whether there is a gain or a loss; it is necessary to be able to prove how that result was reached.
In conclusion, the real challenge for taxpayers is no longer simply declaring their crypto assets, but rather justifying each transaction: proving the origin of funds, demonstrating the chain of transactions, and providing documentary support for every calculation before the tax authorities or a bank. In an increasingly demanding regulatory environment, traceability has become essential for the tax, asset, and banking security of investors. It is precisely at this intersection that Abast Legal’s Digital Assets area operates: we prepare tax reports on crypto assets that include the complete reconstruction of transactions, the analysis of movements between exchanges and wallets, and the documentation of the origin of funds for banking or regulatory compliance processes. This technical and exhaustive work offers taxpayers the necessary guarantees to file their tax returns with complete legal certainty.
By Max Pumares, head of the Digital Assets Area of Abast Legal, and Xavier Casas, lawyer and director of the office of Abast Legal Spain.
