Press Room

20 Jun 2022

Exchange of Information – MAC the Knife


National Technical Director, Andrew Parkes, examines the Convention on Mutual Administrative Assistance in Tax Matters, the international treaty designed to promote international cooperation between tax authorities.

We were reminded recently as to how the world is getting smaller when we were asked a query regarding HMRC’s ability to obtain information.

By now, we believe everyone knows that tax authorities exchange information for various reasons and via various routes, but perhaps not so many people are aware of the OECD/Council of Europe Convention on Mutual Administrative Assistance in Tax Matters aka the MAC – we know the letters are the wrong way round, but CMAA doesn’t roll off the tongues of tax officials as well.

This is a multilateral agreement from way before they became fashionable with the multilateral instrument.

It is a way for countries to agree to exchange information, collect each other’s tax debts and serve documents, although most countries do opt out of the debt collection and document service parts (for obvious reasons!).

I did it my way

Why does it matter, we hear you cry! Well, although the UK has a wide-ranging treaty network, and also a number of Tax Information Exchange Agreements where there isn’t a full treaty, there are still gaps. The MAC fills some of these gaps, possibly most notably for Brazil and the Seychelles. The latter might strike you as being somewhat obsolete on the basis Seychelles is oh so 80s when it comes to tax. However, with the emergence of crypto/fintech/blockchain, Seychelles has repurposed itself and is very much de rigeur in these circles.

So, just because there isn’t a treaty doesn’t mean that HMRC can’t find out what they want to know.

If you have any queries about exchange of information, please contact Andrew Parkes.


Andrew Parkes

Andrew is a highly experienced international tax specialist who worked at a senior level in HMRC’s international teams for over 10 years. He has a wealth of experience and technical knowledge.

Email: Andrew Parkes