Martyn became a partner at KPMG in 1998, starting in the Sheffield and Leeds offices, where he handled a broad range of UK and international tax matters. In 2007, he moved to KPMG’s Private Equity Group in London while also leading the Northern M&A tax team.

Mr. Till managed KPMG's tax relationships with a diverse client base, including multinational corporations, fast-growing owner-managed businesses, and high-net-worth entrepreneurs. His expertise covered UK direct taxation, tax compliance, audits, and liaising with tax authorities and other stakeholders.

Throughout his career, he frequently collaborated with KPMG’s Forensic Accounting teams, contributing to Expert Witness reports on Corporation Tax, Income Tax, Capital Gains Tax, fiscal share valuations, shareholder disputes, and high-net-worth divorce proceedings. Most cases were resolved through negotiation rather than court hearings.

Before joining KPMG, Martyn trained as a Tax Inspector at HMRC (then the Inland Revenue) through its fast-track graduate scheme, qualifying in 1989. He gained extensive experience in UK direct taxation, audits, and investigations into individuals, partnerships, and corporations. He frequently attended the First Tier Tax Tribunal, handling tax appeals, disputed claims, disclosures, and other administrative matters.

Beyond his Tax career, Mr. Till serves as a Trustee and Board Member of a local social enterprise charity.