Amsterdam: Member state officials open the first substantive round of talks on the tax omnibus in Brussels on 23 September 2026, when the Council’s High-Level Working Party on Tax Questions takes up the simplification package the European Commission tabled on 24 June, and Dutch holding and financing structures sit close to the centre of what would change.
The Presidency has put two items on that agenda: the omnibus on taxation, catalogued in Council papers as Omnibus XI, and a recast of the Directive on Administrative Cooperation. Delegates will exchange views rather than negotiate text, which is how unanimity files usually begin.
The package does not invent a new tax. It rewrites the plumbing of six existing instruments at once: the Interest and Royalties Directive, the Parent-Subsidiary Directive, the Tax Merger Directive, the Anti-Tax Avoidance Directive, the Dispute Resolution Mechanisms Directive and the FASTER rules on withholding tax relief. The Commission put the expected saving for business at around 8 billion euro a year.
The Commission presented the package as a "landmark tax simplification" measure designed to streamline compliance and strengthen competitiveness, and set it against a wider target of cutting administrative burden by 25 per cent, and by 35 per cent for small and medium-sized firms, by 2029.
Four changes carry the most weight for cross-border groups:
- An EU-wide research and development allowance written into the direct tax framework
- Narrower controlled foreign company and interest limitation rules, which currently vary sharply between capitals
- Simpler withholding tax relief, the perennial complaint of cross-border investors
- A lighter reporting load under the mandatory disclosure rules for intermediaries
Most provisions would apply from 1 January 2029. That date looks distant until the procedure is taken into account. Direct tax moves under Article 115 of the Treaty, so every capital holds a veto, and the Parliament is only consulted. Three years is a normal timetable for a file of this size, not a generous one.
Litigation supplies the argument for moving. On 15 September 2026 the Court of Justice heard joined cases C-287/25, C-288/25 and C-289/25, OPmobility and Societe Generale, on a French tax integration scheme that keeps the profits and losses of non-resident subsidiaries out of a group’s taxable result. Similar questions have reached Luxembourg repeatedly since the Marks and Spencer judgment two decades ago, and each ruling reshapes national rules that the directives never harmonised.
Tax practitioners meet in Bucharest on 17 September for the CFE symposium on EU tax decluttering, and the questions there track the ones Council delegates will raise. Does an R and D allowance survive contact with treasuries that already run their own credits? Does the DAC recast genuinely cut reporting, or does it move obligations between instruments? Will the withholding tax simplification reach the investors who pay for the current friction?
The background is the Commission’s broader decluttering drive. Twelve omnibus packages have now landed across sustainability reporting, digital rules, agriculture, defence and taxation since early 2025, all of them arguing that European firms lose ground to American and Chinese competitors partly through compliance cost. Critics in the Parliament read the same packages as deregulation with a technical label.
Capitals will judge the file on revenue rather than rhetoric. A member state that has built its corporate base on a particular interest limitation formula loses something when the formula becomes common. The Netherlands, Ireland and Luxembourg host the conduit structures the anti-avoidance rules were written to police, and each will read the drafting closely. The Commission’s June announcement sets out the full scope, and the Working Party on Tax Questions now owns the timetable.
