Martyn is one of the UK's most experienced and trusted regulatory advisers. He brings over 30 years of deep expertise in financial regulation, enforcement, and compliance — spanning public service, private practice, and strategic advisory work at the highest level.

He began his legal career in the UK Government Legal Service, before spending a decade at the Financial Services Authority (FSA), where he played a central role in the development of enforcement policy and regulatory reform.

He then spent more than 21 years as a partner at two of the world's leading law firms — Herbert Smith and Linklaters — both ranked in the top tier of the Legal 500 and Chambers & Partners directories. In both firms, Martyn advised on some of the most complex and sensitive regulatory matters in the UK and globally — including enforcement actions, market conduct, culture reviews, and strategic regulatory issues.

Martyn has been consistently ranked as a top-tier practitioner by both Legal 500 and Chambers for his work in financial services regulatory matters.

Having left “Big Law” in April 2025 Martyn is now working as an independent consultant.