The company says further acquisitions are on the way to support its target of 15% annual growth for the next five years and ambitions to double the size of the business to 600 staff.

Brook Financial was launched by husband-and-wife team Alison and Kevin Smith in 2006 and offers services to business owners that need a wide range of accountancy services but do not have a full in-house finance team. 

The firm provides outsourced financial services, including back office finance team functions, cashflow management, consultancy and payroll.

Alison Smith used to work at Old Mill, while Kevin Smith’s sister, Lorraine Bolland, is a director at Old Mill.

The acquisition, for an undisclosed sum, will see Alison and Kevin become partners at Old Mill followed by full integration of the two firms. All staff at Brook Financial will join Old Mill and become the firm’s specialist financial outsourcing and digital team.

Kevin Whitmarsh, CEO at Old Mill, said: “For many firms, Making Tax Digital is just a tick box exercise, but for Old Mill, digital innovation is a key part of our growth strategy plans and we are fundamentally shifting the business to become more digitally enabled. Investing in Brook Financial is a key part of this shift, so this is an incredibly significant acquisition for us.”

Alison Smith, director at Brook Financial said: “We have worked with Old Mill for many years. Many of our clients are also Old Mill clients - as our services hugely complement each other - so when we were looking to grow our client base, and help more firms to realise their potential, Old Mill was the perfect fit. Not only is Old Mill one of the biggest firms in the region - with a 5000-strong client base - but they share our people-centric culture which focusses on supporting our clients to be successful and nurturing and developing our people to be able to grow in line with our clients' ambitions.”

Old Mill is recruiting with the aim of doubling staff numbers to 600. It is seeking staff to support the integration of the digital services.