RSM UK approves merger with US arm, backing partnership over private equity
Accountancy firm RSM UK has greenlit a merger with its US sister, RSM US, to create a $5bn (£3.75bn) new partnership structure, in the first major transatlantic combination in the accountancy sector.
It was reported last October that both firms were in talks, with a focus on the mid-market. On Thursday, after a “near-unanimous vote” both firms have approved a transatlantic partnership.
The UK arm generated revenues approaching £600m in the year to March 2025, while the US arm reported revenue of $4bn (£2.8bn) in the year to April 2024.
The deal, effective from 1 January 2026, will see a new partnership structure created, comprising 23,000 professionals who will operate across the UK, the US, Canada, Ireland, India and El Salvador.
Brian Becker, RSM US managing partner, will take on the role of CEO of the new transatlantic partnership.
Rob Donaldson, RSM UK CEO, explained, “We have been on a journey to become a more effective competitor to the largest players in the UK market whilst enhancing our ability to support our RSM network partners globally.”
Last October, when the firms were in talks, Becker stated that RSM was not trying to be the ‘Big Five’, but instead was trying to be the ‘Big One’ for the middle market.
The firm has opted for a new partnership model at a time when others in the accountancy sector are looking toward private equity investments. Private equity firm Cinven completed a major investment in its rival Grant Thornton UK last December. A private equity firm, Apax Partners, acquired the accountancy and advisory business of Evelyn Partners for £700m last November.
Donaldson pointed out that over the last 12 months, the firm has already seen new opportunities and tangible client wins that the UK arm would “not have achieved independently”.
Both firms are members of RSM International, a network spanning more than 120 countries, over 800 offices, and more than 64,000 people. Even with this new partnership, it will continue to be an independent member.
The door is also open to the rest of the member firms to join, Becker told the FT: “A lot of [member firms] need the capital to build consulting, advisory or other services, and we have the capital together to do all the investments that we need.”