Portugal Crypto Tax Ruling 2025: Swaps to Stablecoins Not Taxable Before Fiat Conversion

Portugal’s tax authority confirms that crypto swaps to stablecoins like USDC are not taxable if held > 365 days. Learn how the IRS exemption applies.

Introduction

In October 2025, Portugal’s Tax Authority (Autoridade Tributária e Aduaneira, AT) issued a binding ruling (Process No. 28969) clarifying how crypto-asset swaps are treated under the Portuguese Personal Income Tax Code (CIRS).

This new guidance brings much-needed clarity for investors, freelancers, and expatriates trading crypto in Portugal—especially for those converting crypto to stablecoins like USDC before exchanging into euros (EUR).

1. Background: Crypto Tax Rules in Portugal

Since January 2023, Portugal taxes crypto gains under Article 10 of the CIRS. The key points are:

Crypto assets held for over 365 days are exempt from IRS (income tax) when sold.
Short-term holdings (< 365 days) are taxed as Category G income at a flat rate of 28 % (or added to overall income if opted).
Crypto-to-crypto swaps can trigger taxation unless they qualify as purely technical transactions.
Staking or business-related crypto income remains taxable under separate categories.

2. Case Summary (Binding Ruling 28969/2025)

A Portuguese tax resident investor requested clarification after performing the following sequence:

Bought a crypto asset (e.g., BTC).
Held it for more than 365 days.
Swapped it into USDC, because there was no direct pair with EUR.
Immediately converted USDC → EUR.

The question: Does the swap into USDC trigger a taxable event?

3. Key Decision: Only the Fiat Conversion Is Taxable

The AT concluded that:

The technical swap into USDC is not a taxable event, as it serves only to facilitate the euro conversion.
The taxable moment occurs only upon conversion to fiat currency (EUR).
If the original crypto-asset was held for ≥ 365 days, the resulting gain remains tax-exempt under Article 10(19) CIRS.
The exemption applies only when both the taxpayer and counterparty are residents in an EU/EEA country or in a jurisdiction with a double-taxation treaty (DTT) and information-exchange agreement with Portugal.

4. Practical Example

Date	Transaction	Tax Result
Day 0	Buy Bitcoin (BTC)	Acquisition date starts 365-day period
Day 400	Swap BTC → USDC (technical)	Not taxable, no gain recognized
Day 401	Convert USDC → EUR	Tax-exempt, asset held > 365 days

This confirms that long-term investors can sell crypto tax-free even when a stablecoin swap is required, as long as it is immediate, technical, and documented.

5. Why This Ruling Matters

This decision strengthens Portugal’s position as one of Europe’s most crypto-friendly tax regimes.
It confirms that:

Long-term holding (≥ 365 days) is rewarded with full tax exemption.
Technical stablecoin swaps are tolerated and do not reset the holding period.
Proper documentation (timestamps, exchange records, wallet IDs) is crucial to prove the swap was immediate.
Fiat conversions remain the only point where gains are realized for tax purposes.

This clarification provides greater legal certainty for individuals using crypto as income, or freelancers receiving international payments in digital assets.

6. Compliance Checklist for Crypto Holders in Portugal

Before filing your Portuguese IRS return, ensure you:

Keep a record of acquisition dates and wallet addresses.
Track every swap and conversion, including timestamps.
Keep proof that the swap was immediate and technical.
Verify that your exchange operates in an EU/EEA or treaty jurisdiction.
Declare the transaction in Annex G1 (for exempt gains > 365 days).

7. Implications for Freelancers and Expats

For expatriates under the Non-Habitual Resident (NHR) or IFICI regimes, this ruling reinforces that crypto income is treated distinctly from professional or passive income.
Freelancers paid in crypto should still register their professional activity in Portugal, but capital gains from long-term holdings can remain exempt.

GoalSeek regularly assists clients in structuring crypto activities to ensure full compliance with Portuguese tax law while optimizing overall international tax efficiency.

8. Final Thoughts

Portugal’s 2025 ruling confirms that stablecoin swaps like USDC or USDT are not immediately taxable when used solely as a step toward euro conversion.
If you hold your crypto for at least one year and maintain proper documentation, you may benefit from the 365-day tax exemption.

However, the application of this exemption depends on individual residency, the counterparty’s location, and the nature of each transaction.

About GoalSeek

GoalSeek is a Portuguese tax and financial advisory firm specializing in:

Crypto-asset taxation for residents and expatriates
Freelancer registration and VAT compliance
NHR and IFICI tax planning
International tax coordination for foreign income

Our mission is to help you understand, comply, and optimize your tax position in Portugal.

Written by Rui Borges, CPA n.º 84392
Senior Tax Consultant, GoalSeek

Disclaimer: This article provides general information and does not constitute legal or tax advice. Always consult a qualified tax professional or confirm directly with the Portuguese Tax Authority before acting on any interpretation.