> All tax treaties and agreements between countries (including intra-EU) are bilateral country to country agreements.

That is completely wrong on multiple levels.

- You’re likely thinking of the double taxation treaties that follow the OECD model convention. These hardly get refreshed every 7 years. The German/Irish one is from 1962, the French/Irish one is from 1966, and the UK/Irish one from 1976. - The OECD’s BEPS multilateral tax treaty has now 85 state parties, including Ireland - There are other example of multilateral tax treaties, e.g. the Nordic countries have a multilateral double taxation treaty - There’s plenty of EU legislation around taxation covering predominantly VAT and excise duties bit also such details as the tax treatment of moving personal property between member countries or how royalty payments between associated companies are treated