In an increasingly globalized environment, the mobility of companies, capital and professionals poses a constant tax challenge: avoiding international double taxation. For those who operate in more than one country or plan to set up in Spain, knowing and correctly applying international double taxation avoidance treaties (DTAs) is key to efficient, secure and legally compliant tax planning.
What is double taxation and why does it represent a risk?
International double taxation occurs when two States exercise their taxing powers on the same income or assets of a taxpayer. For example, a professional resident in France who earns income in Spain could be taxed on that income in both countries if the agreement in force between the two jurisdictions is not correctly applied.
This situation, in addition to increasing the tax burden unnecessarily, can affect the competitiveness of companies, distort investment decisions and hinder the internationalization of businesses.
Double taxation treaties in Spain: legal and technical framework
Spain has a solid network of more than 90 bilateral treaties to avoid double taxation, signed with states around the world. These treaties, largely based on the OECD Model Convention, establish criteria such as:
- Which State has the right to tax different types of income (corporate profits, dividends, interest, royalties, labor income, etc.).
- Methods to eliminate double taxation, either through exemption or deduction for international double taxation.
- Procedures for the exchange of information and resolution of conflicts through amicable agreements.
The provisions contained in these treaties must be applied in conjunction with Spanish domestic legislation and the European directives on administrative cooperation in tax matters (DAC).
The role of DAC directives: transparency and fiscal control
In this context, the European Union has developed a parallel regulatory system that reinforces the DTAs through the Directives on administrative cooperation in the field of taxation (DAC1 to DAC8).
Among them, two stand out:
📌 DAC6 (EU Directive 2018/822):
It introduces the obligation to declare certain potentially aggressive cross-border arrangements by tax advisors, lawyers and companies. It aims to prevent structures that can be abused by taking advantage of regulatory fragmentation between countries, including DTAs.
This framework helps to protect the integrity of the agreements and prevents them from becoming vehicles for tax avoidance.
📌 DAC8 (EU Directive 2023/2226):
It is the most recent and must be implemented by member states by December 31, 2025. This directive extends the automatic exchange of information to cryptoassets, cryptoasset service providers (CASPs), digital platforms, and NFTs.
Among its main implications:
- It obliges exchanges and platforms to report their users’ transactions to the national tax authorities.
- Introduces due diligence requirements and harmonizes the tax treatment of cryptoassets in accordance with the OECD’s Crypto-Asset Reporting Framework (CARF).
- Strengthens tax traceability and international compliance for taxpayers using digital assets.
Both DAC6 and DAC8 are closely related to the IDCs by complementing their application with proactive transparency measures and automated tax monitoring, especially in complex or digital cross-border transactions.
The technical complexity of implementing a CDI
Although the agreements are designed to provide legal certainty, their practical application is often complex and subject to multiple constraints:
- Correctly determine the taxpayer ‘s tax residence.
- Classify rent as stipulated in the applicable agreement.
- Comply with the formal requirements, such as the tax residency certificate issued by the tax administration of the country of residence.
- Take into account anti-abuse clauses or limitations of benefits that may restrict the application of the agreement if it is considered that an improper use of the agreement is intended.
All this requires advanced technical knowledge and precise coordination between the different national and international legal frameworks.
Why trust Advixy?
At Advixy, we understand that operating internationally involves more than just complying with tax formalities. It is about building a solid, transparent tax strategy adapted to current regulatory challenges.
We have a team specialized in:
✅ International and digital taxation
✅ Practical application of bilateral treaties and DTAs
✅ Assessment of obligations under DAC6 and DAC8
✅ Advice to companies and self-employed with operations in more than one country
✅ Application of the ZEC regime and other tax advantages in Spain
Thanks to our experience in complex environments, we help our clients prevent tax risks, optimize their tax burden and ensure regulatory compliance both in Spain and in their home countries.
International double taxation treaties, together with the progressive implementation of directives such as DAC6 and DAC8, are shaping a regulatory ecosystem that is more demanding, but also more transparent.
The correct application of these tools can make the difference between inefficient taxation and a sustainable competitive advantage. At Advixy, we help you navigate this international environment with legal certainty, strategic vision and expert support.
📩 Do you have doubts about the application of an agreement in your case?
Contact us. We help you make fiscal decisions that are safe, sustainable and aligned with the new European and global standards.
