Professional services firm AAB has expanded its operations in Ireland through the acquisitions of Old Quarter Chartered Accountants and O'Brien Crowley Chartered Accountants. The transactions mark AAB's seventh and eighth investments in Ireland since 2025 and further increase its advisory, audit and tax capabilities in the market.

Business Sale Report reported that the two firms will relocate to AAB's new 23,000 sq ft office at Barrack Square in Ballincollig, County Cork, following completion of the acquisitions. The combined business will employ close to 300 people in Ireland and more than 1,500 across 17 locations.

Old Quarter Chartered Accountants, founded in 2022, operates from Cork and Kerry with 26 employees under partners Mark O'Keefe, Joe Foley and Diarmuid Kelleher. The practice provides audit, tax, business advisory, payroll and company secretarial services to a growing SME client base.

O'Brien Crowley Chartered Accountants, established in 1985 and led by partner Killian O'Brien, employs 13 people in County Cork. The firm delivers financial reporting, audit, tax, advisory and payroll services to businesses across Ireland.

Colm Duggan, head of professional services at AAB in Ireland, said: "We’re building scale at pace, but importantly, we’re doing it in a way that strengthens the quality of our client relationships and the depth of our expertise."

He added: "AAB is the partner of choice for Irish accountancy firms looking to grow and to enhance their offering to clients, bringing together the right people, insight and ambition to deliver real value for clients. We will continue to grow across Ireland and the UK both organically and by acquisition."

Mark O'Keefe, partner at Old Quarter Chartered Accountants, said joining AAB would enable the firm to maintain its client relationships while providing our clients with access to broader expertise, greater resources and international reach.

Killian O'Brien said: "Joining AAB will allow us to access the technological capabilities and expertise which comes with an international platform, providing opportunities for our clients and our people."