Global Minimum Tax 2026: what groups with more than €750M must do

Key data

Business groups with more than 750 million euros in consolidated annual income have had, since March 30, 2026, a new coordinated framework that regulates how the global minimum tax is applied in Spain, including the foral territory of Navarre. The Resolution of March 30, 2026 from the General Secretariat of Territorial Coordination publishes the agreement reached in the Cooperation Board between the General State Administration and the Foral Community of Navarre.

The agreement responds to a specific need: Navarre has its own tax powers and has approved its own regulation —the Foral Law 18/2025, of December 22— to implement OECD Pillar 2. Without coordination, groups operating in Navarre could face conflicts of jurisdiction between the foral regime and the state regime. This agreement resolves them.

What does this regulation establish?

The agreement coordinates the application of the complementary tax to ensure a minimum global level of taxation, internationally known as OECD Pillar 2. This mechanism requires large business groups to pay tax, at minimum, an effective 15% on their profits, regardless of which jurisdictions they operate in.

The mechanics work as follows: if a group pays tax below 15% in any jurisdiction, the complementary tax acts as a "top-up" that covers the difference until reaching that minimum threshold. The objective is to prevent multinationals from artificially reducing their tax burden by taking advantage of low-tax territories.

In Spain, the application of this tax has added complexity: Navarre has a special tax regime with its own tax powers recognized constitutionally. This means the Foral Community can legislate on tax matters autonomously, as it has done with Foral Law 18/2025. The published agreement ensures that both frameworks —the state and the Navarrese foral— are coherent with each other and do not generate situations of double regulation or jurisdictional conflict.

Economic and operational impact

For affected groups, the impact is not only fiscal: it is also operational and compliance-related. Having to comply with two coordinated regulatory frameworks —the state and the Navarrese foral— implies greater complexity in calculating the consolidated effective rate and in presenting tax information.

Tax departments and CFOs of affected groups must now ensure that their tax planning takes into account not only the state framework of Pillar 2, but also the specificities of Foral Law 18/2025 when the group has activity or entities in Navarre. Any difference in foral treatment that is not properly coordinated can generate tax contingencies.

From a business perspective, the complementary tax can have a direct impact on the net profitability of groups that until now benefited from tax structures with effective rates below 15%. The agreement does not create new obligations beyond those already established by Pillar 2, but it does clarify the applicable framework in Navarre, which reduces legal uncertainty for groups with presence in that territory.

Who does it affect?

• Multinational groups with consolidated income exceeding 750 million euros annually operating in Spain, especially if they have entities or activity in Navarre.
• Large-scale national groups that exceed the 750 million euro threshold in consolidated income, even if they have no international presence.
• CFOs and tax directors of affected groups who must review the calculation of consolidated effective rate under the new coordinated framework.
• Tax advisors and consulting firms that provide services to groups with presence in Navarre and need to understand the interaction between the foral regime and the state regime.
• Groups with tax planning structures that have operated with effective rates below 15% in any jurisdiction and must now review those structures.

Practical example

A multinational group headquartered in Spain, with consolidated income of 1,200 million euros and a subsidiary with significant activity in Navarre must now manage its compliance under two coordinated regulatory frameworks.

If the group has a consolidated effective rate of 12% in any of its operating jurisdictions, the complementary tax acts to cover the difference up to the 15% minimum required. The novelty of the State-Navarre agreement is that, for the part of activity attributable to the foral territory, the calculation base and treatment follow Foral Law 18/2025, while the rest of the group follows the state framework. The agreement ensures that both calculations are coherent and no double taxation or taxation gap occurs.

Without this coordination agreement, the group could face divergent interpretations about which administration —the state or the Navarrese foral— has jurisdiction to collect the complementary tax corresponding to activity in Navarre. The agreement eliminates that uncertainty.

What should companies do now?

1. Verify if you exceed the threshold: Check if the group's consolidated income exceeds 750 million euros annually. If so, the complementary tax applies to you.
2. Identify presence in Navarre: Determine if the group has entities, permanent establishments or significant activity in the Navarrese foral territory. If so, Foral Law 18/2025 is relevant to your compliance.
3. Calculate the consolidated effective rate: Review the group's actual effective rate in all jurisdictions where it operates. If any falls below 15%, the complementary tax will cover the difference.
4. Review current tax planning: Analyze whether the group's current tax structures are compatible with the new State-Navarre coordinated framework. Structures designed to reduce taxation below 15% must be reviewed.
5. Coordinate with specialized advisors in foral taxation: Engage tax consultants with expertise in Navarrese foral law and the interaction with state tax law to ensure proper compliance and avoid contingencies.