Ronan qualified as a Chartered Accountant with Price Waterhouse in Scotland in 1998 and worked with them in the UK, France, and Switzerland, primarily with financial services clients. He later joined EY, working with clients in the UK and the USA.

Having always intended to return to Derry and the North West, he moved back to Ireland in 2005 to join an established family firm providing accountancy and insolvency services. Ronan is a Registered Auditor and a licensed Insolvency Practitioner, qualified to act in both the UK and Ireland. He has extensive experience in insolvency and restructuring, covering both corporate and personal cases.

More recently, Ronan co-founded a UK-based online accountancy and advisory firm, Toast, whose primary goal is to provide high-quality, real-time accountancy advice for ambitious SMEs.