Publication of an impressive report by the Commission on DAC. Does the Commission suffer from a democratic deficit ? Impact of DAC2 on the capital gains tax in Belgium ?

Monday, 1 December, 2025

The Commission has recently published its evaluation of the EU Directive on Administrative Cooperation in Taxation (DAC) (full report [1]).

It is often said the the EU Commission is undemocratic. This report shows in my view the contrary. The report is based on several sources such as :

▶️ a public consultation conducted by the Commission;

▶️ feedback provided by Member States and private stakeholders, including replies to questionnaires;

▶️ additional targeted consultations conducted with academics, tax lawyers and economists to gather their comments on specific aspects of the DAC. In this context, I had the honour of being invited to share my thoughts on the DAC, together with my esteemed colleague Daniel Gutmann. Many thanks to Julien DODELER, Henrik Paulander, Katarina Žnidaršič, Francesca Marangoni for the invitation and the interesting discussion!

1️⃣ Impact of DAC2 for the new capital gains tax (10%) in Belgium (entry into force : 1/1/2026)

⚠️ The report shows that the exchanges relating to gross proceeds from redemptions and sales of financial assets are, in terms of value, the category of financial information exchanged corresponding to the largest amount (apart from the value of the accounts), i.e. EUR 4,061 billion since 2018!

🔅 The Belgian tax authorities will most certainly use this information in order to monitor whether capital gains on financial assets (realised as from 1/1/2026) held abroad are correctly declared by Belgian individual taxpayers in their income tax returns!

⚠️ This will presumably give rise to discussions between taxpayers and the tax authorities, given that the “gross proceeds” do not reflect the taxable “capital gains”.

2️⃣ Findings regarding DAC6

🔶 Approximately 6,600 (agressive) cross-border arrangements have been reported per year by the Member States in the dedicated central directory;

🔶 The vast majority of arrangements reported originates from a few Member States: Germany, the Netherlands, Cyprus, Luxembourg, Ireland and Poland.

🔶 Most of the arrangements reported concern Hallmarks A (generic hallmarks linked to the main benefit test, 35%) and B (specific hallmarks linked to MBT, 34%).

🔶 DAC6 information is used by the majority of Member States. In January 2023, 21 Member States had already integrated DAC6 data into their risk assessment process, and 16 Member States were using the data received for specific tax inspections or extended tax audits!

🔶 DAC6 is posing interpretative challenges for the Member States, leading to different interpretations and application of the DAC6 provisions across them => this creates uncertainty among intermediaries and increases the burden and the associated (compliance) costs!

Find here the link to the book of Aymeric Nollet and myself on DAC6.