Independent accountancy and business advisory firm Johnston Carmichael, part of the Moore Global network, has reinforced its presence in London with two senior promotions, showcasing the firm’s commitment to expanding its footprint in the UK’s financial capital.

Si Mathavan has been appointed London Office Head, while Simon Cavell has been promoted to Consulting Director. The firm’s London office is located within the City and is home to Johnston Carmichael’s specialist Risk Assurance and Consulting teams, serving clients across many sectors, including financial services.

The firm, which was founded in the North East of Scotland almost 90 years ago, opened its first London office in 2019 and since then has seen significant expansion. It also plays a prominent role in the firm’s membership of Moore Global.

Si Mathavan joined Johnston Carmichael as a Partner from a Big Four firm, and has over 20 years of experience in internal audit, process and controls, corporate governance and regulatory compliance. He has supported clients of various sizes in the technology, media, not-for-profit, financial services and energy sectors, and has led engagements covering internal audit, regulatory assurance, ESG strategy, and transaction advisory projects as part of M&A transactions.

A trusted adviser to both clients and regulators, Si has delivered internal audit services through both co-sourced and fully outsourced models and advised on industry-wide regulatory change initiatives. His expertise has been key to developing the firm’s internal audit and regulatory assurance capability and positioning Johnston Carmichael as an authority in risk consulting.

As London Office Head, Si will lead the firm’s continued growth in the capital, deepening connections across the market, especially amongst mid-market firms, and supporting growth across consulting, audit, and advisory disciplines.

Simon Cavell, who becomes Consulting Director, joined Johnston Carmichael in 2022 with nearly 30 years of senior experience in financial services. He has held executive roles spanning customer experience, operations, change, product management, strategy, risk, and HR. His track record includes launching retail funding operations overseas, transforming customer service functions, and developing strategic propositions for large financial institutions.

Simon has successfully worked with a range of clients including high street banks and building societies. He has also been at the forefront of Johnston Carmichael’s response to the Financial Conduct Authority’s Consumer Duty requirements, supporting clients with practical, outcome-focused guidance.

Simon recently completed the firm’s in-house, Masters-accredited Leadership Programme, and uses his experience and insight to mentor junior team members.

Lynne Walker, CEO of Johnston Carmichael, commented: “Si and Simon have shown great leadership since joining the firm, delivering positive impact for our clients and colleagues, and growing our community in London. 

“Both have boosted our strong culture, and I look forward to seeing them shape the next chapter of our success in the capital.”

Mark Houston, Senior Partner and Chair of Johnston Carmichael, added: “With almost 90 years behind us, and ambitious plans for growth, it is vital that we develop our next generation of leaders.

“Si and Simon have made a fantastic contribution to the firm in recent years and are very much part of that future and the legacy we continue to build.”

In recognition of the firm’s focus on its people, Johnston Carmichael was recently accredited as a Great Place to Work. It has since built on its certification with a listing in Great Place to Work’s 2025 UK Best Workplaces for Development.