Spain’s 2026 Annual Tax and Customs Control Plan was approved on 11 March 2026 by the Spanish Tax Authorities and published in the Official State Gazette on 12 March 2026.

The 2026 Plan takes the review of related-party transactions to an unprecedented level. While previous priorities remain in place, the authorities have clearly signaled an increase in audits targeting large companies and corporate groups, a strengthening of the Large Taxpayers Unit, and a deeper, more substantive review of supporting documentation. The message is clear: formal compliance alone is no longer enough.

What will the Tax Authorities focus on in 2026?

Traditional risk areas remain unchanged:

  • Business restructurings and transfers of intangible assets
    • Royalty payments and intra-group services that reduce the tax base
    • Loss-making entities on a recurring basis
    • Related-party financing arrangements
    • Offshore structures retaining profits that should be taxed in Spain

In addition, several key developments stand out:

✔ Substance over form. The Plan explicitly states that transfer pricing reviews will go beyond formal documentation requirements and focus on the actual functions, assets and risks of each entity. A Local File that is formally compliant but lacks substance will not provide protection.

✔ Low-risk entities under scrutiny. Entities characterized as “low-risk” within a group will continue to face increased attention. Tax Authorities will assess whether this classification reflects the economic reality of the transactions.

✔ Tax groups: new areas of focus. For the first time, the Plan introduces a specific section on groups, targeting those with unusually low turnover, lacking clear business rationale or with limited real intercompany activity. The advanced VAT group regime will also be reviewed to ensure the correct treatment of intra-group services.

✔ Digitalisation as a risk driver in transfer pricing. The Plan explicitly links transfer pricing risk to the digital economy, signaling closer scrutiny of digital business models and intra-group transactions in tech-driven environments.

✔ Active monitoring of transparency reports. The Tax Authorities will not simply review reports submitted under the Code of Good Tax Practices. They will also hold bilateral meetings with taxpayers to clarify or expand on the information provided where necessary.

✔ Pillar Two (Top-up Tax): from planning to implementation. The first filings will be submitted in 2026, and the Tax Authorities are beginning to build their control framework, starting with identifying affected taxpayers. In parallel, the OECD’s “Side by Side” package, approved in January 2026, introduces significant changes that—although reportable from 2028—require immediate attention.

Our recommendation

At addwill, we recommend reviewing and updating your transfer pricing policies and documentation to ensure compliance and mitigate audit risks.

You can download the full 2026 Plan guidelines here.

We support companies in assessing their related-party transactions and preparing transfer pricing documentation within the required deadlines. Our tax expertise allows us to deliver tailored analysis aligned with your business model and group structure.

If you have any questions, our tax team at addwill is here to help. Feel free to reach out, we will be happy to assist.