Who I Help

Family-owned businesses. SMEs. Multinational corporations. Clients across all sectors.

How I Help

Audit and assurance. Strategic advisory. Tax planning and compliance. Transaction advisory. Succession planning. Business mentoring.

“Understanding what matters most to your client.”

Killian O’Brien is a Partner at AAB, based in Cork. He trained in audit before moving into transaction advisory services and later developed his expertise in taxation and became a Chartered Tax Adviser. That combination of large-firm training and hands-on experience running his own practice gives Killian a unique perspective, and he now offers clients a fully integrated suite of services spanning audit, tax and strategic advisory. He works with a broad range of clients, from family-owned businesses and SMEs through to multinational corporations across all sectors and is known for reacting quickly and practically whenever a client needs support.

Reactive by Design

No two weeks are exactly the same, which is one of the things I enjoy most about my role. My week is typically split between supporting and mentoring my team in the performance of their roles and then taking the output from their work and using it to advise our clients as part of their strategic decision-making. My role requires me to be very reactive; if a problem arises for a client, my goal is to be part of the solution as quickly as possible.

From Numbers to Strategy

I always enjoyed numbers in school, particularly maths and applied maths, and my father was an accountant, so that world was always familiar to me at home. Over time, I began to see accounting as a way of developing my connection to numbers in a way that would help people and provide me with a fulfilling career. I first turned to audit within a large firm setting which was extremely rewarding and offered me the opportunity to travel all over the world. The real turning point came when I decided to move home to Cork and become involved in my father’s accounting practice, which marked the shift from processing and analysing numbers to viewing numbers as an input into the strategic process.

Perspective

My experience gives me a unique perspective, because I’ve worked on both sides of the table. I have the technical training and professional expertise gained from working in a large practice, but I also understand the realities and pressures of running a business, having operated as a sole practitioner. I’ve experienced the challenges of managing cash flow, making investment decisions, growing a team and balancing competing priorities, and that rounded experience allows me to provide advice that is both technically sound and commercially practical.

Running the Business, Not Just the Numbers

One of the biggest challenges I faced in my career was making the move from a large firm into a small practice. While my training and experience to date had been grounded in strong technical knowledge, I quickly realised that running a business involves so much more than just managing the numbers; it requires balancing people, operations, strategy and risk. That experience taught me the importance of listening, maintaining perspective and focusing on practical solutions, and it’s a lesson I apply every day when advising clients.

Finding the Common Connection

I always focus on understanding the person behind the business first. I really enjoy those initial meetings, getting to know clients personally and understanding what motivates them. You will always find a common connection, whether it’s a mutual acquaintance, sport, travel or family life.

Confidence in Decision-Making

The most satisfying aspect of the role is helping clients gain confidence in their decision-making and seeing the positive impact that has on their business. Whether it’s helping them overcome a challenge, identify an opportunity or achieve a long-term goal, it’s rewarding to know you’ve played a part in their success. The greatest compliment a client has given me is telling me they feel I care about their business as much as they do.

I’m looking forward to tapping into the collective experience and expertise AAB has brought together to discover even more opportunities to help my clients.

Unlocking Potential

I’m always mindful of finding the right complement of people and technology. It’s important to embrace technology, but not at the expense of developing your people; our value must derive from our people, and technology is the tool we give them to reach their full potential.

A common misconception about the profession is that we deal only in historical information and aren’t forward thinking, when in fact, we’re often perfectly placed to foresee the challenges a business will face and help navigate accordingly.

I am looking forward to exploring innovative ways to leverage technology as well as the strength and depth of my new team to enhance the services we provide to clients.