Founded by Marilyn and Jonathan Brathwaite, Mithril delivers private-client-level service to owner-managers underserved by institutional players.
Marilyn and Jonathan were both born in the United Kingdom. Marilyn's mother is Barbadian; Jonathan's parents are both Barbadian, and he was raised on the island. They live and work in Barbados, with active operations in Canada and Florida.
Marilyn spent seventeen years at a multinational corporation across the UK, Ireland, and EMEA, managing a P&L in excess of USD 500M with responsibility for contract management, SOX corporate governance, and financial disclosure. For the past six years she has worked with owner-managers on international business and wealth structures, trusts, and operating companies.
Their work focuses on the structures, treaties, and relationships that let Latin American owner-managers operate confidently across borders, with a deliberately small client roster.
Mithril's senior team works directly with every client. Engagements are partner-led; nothing meaningful is delegated downstream.
Rianna leads private-client engagements at Mithril, working closely with Latin American families on cross-border tax, trust, and corporate matters. She holds a bachelor's degree in Hospitality and Tourism Management and is a member of the Society of Trust and Estate Practitioners (STEP).
Rianna is actively working through the STEP qualifications and contributes to the STEP Barbados branch.
Jonathan is an international tax lawyer who has worked independently for over fifteen years across the United Kingdom and Barbados, with clients connected to Barbados, Canada, Mexico, Brazil, the United States, and Switzerland. He specialises in compliant, commercially workable cross-border tax structures for owner-managed international businesses, investment funds, and private clients, drawing on a wide range of corporate, trust, and business solutions, and has led service teams to deliver on the advice given.
He holds a Master of Laws (LLM) in International Tax Law from the University of Florida's Fredric G. Levin College of Law and is completing a Doctor of Juridical Science (SJD) in International Taxation at the same institution. He also holds an LLB from the University of Wolverhampton, an MSc in Mathematical Finance from Imperial College London, and a BSc in Business and Computing from Brunel University. Jonathan is an Attorney at Law in Barbados, was called to the Bar in England and Wales, and is a member of the Barbados branch of the International Fiscal Association (IFA).
Avondale House, Bank Hall, Saint Michael BB11078
Working relationships with senior Canadian professionals supporting USA, LATAM, and Canada flows.
On-the-ground presence for clients operating through the Port of Miami corridor.
We work with a small number of clients we know well, and only operate structures we understand.
Cross-border strategy built on the USA-Barbados and Canada-Barbados double tax treaties.
Practical, commercially sensible structures, set up correctly the first time and operated through the lifecycle.
Personal attention typically reserved for ultra-high-net-worth families, applied to owner-managers below the institutional threshold.
Mithril International is not a licensed law firm. Formal legal and tax opinions are delivered by appropriately licensed professionals: our in-house tax counsel and our partner attorneys in the United States and Canada. Mithril sources, drafts instructions to, and liaises with external counsel so clients receive correct advice and have it implemented correctly.
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