Subscribe

Effective June 25, 2018 · Published May 15, 2026

EU DAC6: Mandatory Disclosure of Cross-Border Tax Arrangements

DAC6 (Council Directive 2018/822/EU) amended the EU Directive on Administrative Cooperation to require mandatory disclosure of cross-border tax arrangements that meet certain predefined 'hallmarks'. Intermediaries, and in their absence, taxpayers themselves, must report qualifying arrangements to the relevant national tax authority, which then shares the information automatically with all other EU member states through a central EU register. The regime is designed to give tax authorities early sight of potentially aggressive or opaque planning before revenue is lost.

For family offices, the practical impact is significant. Because many family offices act as in-house advisers, structuring vehicles, or administrators for cross-border wealth arrangements, they may qualify as 'intermediaries' under the directive and carry the primary reporting obligation. Where legal professional privilege or a non-EU structure removes an intermediary obligation, it falls to the relevant taxpayer, typically the family or its holding entity. Arrangements already in place before the regime's reporting window opened had to be disclosed retroactively; going-forward obligations apply within 30 days of an arrangement becoming available, ready for implementation, or implemented (whichever is earliest).

Who is affected

  • Family offices that design, market, organise, or administer cross-border tax arrangements involving at least one EU member state
  • Ultra-high-net-worth families with cross-border holding structures, trusts, or financing arrangements touching EU jurisdictions
  • Non-EU advisers and trustees whose clients have EU tax residency or EU-source income, where the taxpayer then holds the residual reporting duty

Key changes

  • Five hallmark categories (A-E) define reportable arrangements, covering generic aggressive features, specific cross-border transfer pricing, beneficial ownership opacity, and automatic exchange-of-information circumvention
  • The 'main benefit test' applies to most hallmarks, meaning an arrangement is reportable only if obtaining a tax advantage is one of its principal expected benefits, but Category D (AEOI/beneficial ownership circumvention) and Category E (transfer pricing) hallmarks apply without this test
  • Each EU member state transposed DAC6 into national law, so penalty regimes, interpretive guidance, and any domestic extensions vary materially across jurisdictions; the UK adopted an equivalent regime domestically following Brexit

Recommended action

Conduct a hallmark screening of all active and contemplated cross-border arrangements involving EU member states, document the analysis and any privilege claims in writing, and establish a standing internal process, with clear ownership, to assess new arrangements for DAC6 reportability within the 30-day trigger window. Where any doubt exists on intermediary status or hallmark application, obtain jurisdiction-specific legal advice before the reporting deadline, as penalties for late or non-disclosure can be material.

Sources

  1. [1]Council Directive 2018/822/EU of 25 May 2018 (DAC6)— EUR-Lex / Official Journal of the European Union
  2. [2]DAC6 – Mandatory Disclosure Rules (Administrative Cooperation)— European Commission — Directorate-General for Taxation and Customs Union
  3. [3]Mandatory Disclosure Rules — BEPS Action 12 Final Report— OECD