Accounting firm RSM has finalised an agreement for RSM Mexico to enter its transatlantic partnership, extending the partner-owned model further into North America and bringing RSM Ireland into a combined platform spanning the US, Canada, Mexico, the UK and Ireland, as reported by the International Accounting Bulletin. The deal adds integrated teams in India and El Salvador to the partnership's operational footprint.

The International Accounting Bulletin reported that the combined platform will comprise more than 25,000 professionals and generate in excess of $5bn (approximately €4.6bn) in annual revenue. The agreement remains subject to definitive documentation, required corporate and regulatory clearances, and completion of closing conditions.

Brian Becker, CEO of the RSM transatlantic partnership, said the addition of Mexico would strengthen the firm's ability to support clients operating across North America's most important trade routes, and added: "Adding Mexico to our already robust partnership between the US, the UK, Canada and Ireland represents continued progress toward our ambition of building a $10bn multinational partner-owned platform dedicated to serving dynamic, growing businesses around the world."

Alfonso Elias, managing partner of RSM Mexico, said joining the transatlantic partnership would strengthen the firm's ability to support clients as they transform for the future, and added: "Clients with global operations will also benefit from our closer connectivity with the US, Canada, the UK and Ireland."

The transatlantic partnership was launched on 1 January 2026 as a partner-owned platform focused on service quality, talent and growth. Under its structure, firms jointly pitch for work, share revenue and pool profits for the purposes of calculating partner retirement payments, providing a model designed as an alternative to outside private equity investment.

The expansion comes as private equity-backed rivals accelerate their own international consolidation. Grant Thornton US, which sold a stake to New Mountain Capital, has acquired more than a dozen firms globally, while US consultancy Crowe recently sold a stake to KKR, with its chief executive indicating that overseas acquisitions would be considered going forward.

RSM's move to build a partner-owned multinational platform positions it as a structural alternative to the private equity-backed consolidation model now reshaping the mid-tier accounting market globally, with direct implications for RSM Ireland's competitive positioning and client proposition in cross-border engagements.

View the full report on RSM Mexico joining the transatlantic partnership.