Executive Summary
The year 2025 was fiscally intense in preparing new reporting obligations and in capitalising on fiscal opportunities that were closing their access window. The **ZEC** experienced its year of highest demand, with the registration deadline closing at end-2026; **Pillar Two** completed its second year of application with all obliged groups fully operational; and **DAC8** — on crypto assets — advanced towards its transposition, anticipating the largest wave of crypto information obligations in the history of Spanish taxation.
Tax revenue reached a new estimated maximum of €298 billion, driven by sustained economic growth and the maturity of the AEAT’s cross-referencing information systems, which allowed detecting and regularising discrepancies with growing effectiveness.
Key Highlights
The ZEC (Canary Islands Special Zone) became the most strategically relevant tax instrument of the year for international groups and domestic companies with eligible activities. The 4% Corporate Income Tax rate on the special base, combined with the programme extension to 2026 and compatibility with Pillar Two for high value-added activities, generated extraordinary demand for eligibility evaluations and structuring services. At BMC, the tax team deployed a specialised ZEC analysis service combining activity eligibility assessment, planning of employment and investment requirements and modelling of net tax savings under different scenarios.
Pillar Two consolidation in its second year of application allowed obliged companies to operate with greater confidence and precision. The first reviews of declarations filed in 2024 revealed some interpretive grey areas — especially in calculating covered taxes and applying the substance-based income exclusion — that the OECD and each country’s tax authorities clarified through additional interpretation guidelines.
DAC8 preparation dominated the activity of the financial services and crypto sector. Companies had to begin implementing tax client information collection systems (tax KYC procedures equivalent to CRS requirements), adapt their platforms for reporting in the required technical format and train their compliance teams on the new requirements.
Analysis by Tax Category
Corporate Income Tax and ZEC: The combination of the standard 25% rate with the ZEC 4% rate on the special base generated sophisticated planning structures for groups with eligible activities. Analysis of the maximum applicable special base — which depends on the number of employees and transaction volume — was determinative in quantifying the net tax benefit of each ZEC structure.
Personal income tax and the reduced working week: The reduction of the maximum working week to 37.5 hours had implications for the taxation of overtime and the structure of salary supplements in agreements that managed it as a pay increase rather than an effective reduction in working hours. Analysis of the personal income tax treatment of different implementation modalities was the subject of frequent queries.
AI taxation: The use of AI systems as business assets raised questions about depreciation, deductibility and corporate tax treatment that current regulations did not specifically address. Analogical application of rules on intangible assets and software was the most frequent technical response, pending specific regulatory development.
Regulatory Changes
DAC8 transposition was the most significant legislative task of the year in the fiscal sphere, with the deadline of 31 December 2025. Crypto sector companies had to monitor the Spanish transposition process and adapt their systems and procedures to the final text of the Spanish law.
Year-end tax planning incorporated ZEC as a central variable in the structures of groups with eligible activities, with the horizon of the registration deadline closure as an incentive for decision-making.
Outlook
The 2026 financial year would bring the definitive closure of ZEC registrations, the first DAC8 information campaign on crypto assets for the 2026 financial year and the extension of CSRD obligations to a wider universe of companies. For companies that had not yet evaluated their ZEC eligibility, the first months of 2026 would be the last opportunity to begin the analysis and registration process.
Our Spanish and international taxation team positioned itself as the reference adviser in maximising available benefits within the applicable regulatory framework, with a special focus on ZEC opportunities and Pillar Two management.
