RSM US and RSM UK to form transatlantic partnership
RSM US LLP and RSM UK Holding Limited yesterday announced that they will form a transatlantic partnership on January 1, 2026.
Partners of both mid-market accounting and consulting firms cast near-unanimous votes in favor of the new US-led partnership.
In the works since October 2024, the deal falls short of the full financial merger that was proposed at the time, and will instead maintain the US and UK firms as independent member firms of the RSM International network.
It will, however, create a new leadership structure that spans the US and UK firms and dictates partner pay, with US leader Brian Becker serving as chief executive.
In a press release, the firms said the structure will align “governance, including a common approach to financial incentives, client service, and future growth investments.”
The structure brings together 23,000 professionals across the US, Canada, Ireland, India, and El Salvador, with aggregate revenue of $5 billion – approximately half of the global network’s annual revenue of $10 billion.
RSM US previously merged with RSM operations in Canada, and RSM UK absorbed RSM Ireland in 2023.
RSM US has 17,000 employees and $4 billion in annual revenue, while RSM UK has 5,400 employees and £600 million in annual revenue.
"We are excited to create a new transatlantic partnership with shared values, enhanced reach and connected resources,” Becker said. “The nearly unanimous vote in favor shows that partners from the US, the UK, Canada, and Ireland are excited to join forces to build a future where we are in an even stronger position to serve the evolving needs of clients and cement our position as the preeminent provider of services designed for the middle market.”
The looser structure also allows for scaling up the business via inclusion of other RSM member firms in the future.
“This next step marks a defining moment in the journey of our firms on both sides of the Atlantic,” said Rob Donaldson, RSM UK CEO. “In today’s rapidly evolving market, our new partnership helps us make quicker, bolder decisions, and investments to serve clients around the world.”
Donaldson added that they have already seen client wins that the two firms could not have achieved independently.
The transatlantic partnership is an effort to drive scale, collaboration, and synergies (including in emerging technology investments) that eschews the private equity ownership embraced by other mid-market accountancies.
Notably, Grant Thornton US was acquired by New Mountain Capital in 2024 and has since expanded into a multinational platform with the bolting-on of Grant Thornton member firms for Ireland, Benelux, France, and Spain, among others.
