Exchange of Information: Key concepts: Legal gateways
In order for HMRC to disclose information to another tax authority, we must have a legal gateway. These gateways are based on exchange agreements signed between the UK and others, and brought into law through Regulations (IEIM200010).
The UK is also a party to two multilateral agreements, whereby many jurisdictions agree through the same instrument to exchange with all other parties. These are:
The OECD/Council of Europe Multilateral Convention on Mutual Administrative Assistance in Tax Matters. This agreement has been ratified by nearly 100 jurisdictions, and the number is increasing (IEIM210300); and
The Directive on Administrative Cooperation in Taxation provides a legal gateway for exchanging with other Member States of the European Union (IEIM210400).
There is more guidance on the legal framework at IEIM200000+.