CT senior partner Jeremy Chittleburgh, who worked with McMillan throughout her time at CT, said: ‘It is with great sadness that we share the news of Moira’s sudden passing. Our thoughts and deepest sympathies go out to her partner Susan and wider family at this difficult time.

‘For over three decades, Moira was part of the CT fabric where her impact on colleagues and clients alike was immeasurable. Her warmth, intelligence, dedication, and the sheer joy she brought to every interaction will be deeply missed.’

McMillan had been with CT for over 30 years since 1992, and was director of personal and business tax, working with clients across the UK. Her career started at Big Four firm EY as a personal tax adviser before joining Chiene+Tait before it rebranded as CT.

She established herself as a leading adviser in this area, and has been remembered for her ‘intelligence, pragmatism, kindness and great sense of humour’.

Michelle Fallon, a CT personal tax partner and close associate of McMillan, said: ‘We are all shocked and saddened by Moira’s sudden passing. She was much more than a colleague to myself and the team at CT who considered her a dear friend, mentor and role model. She was a wonderful person to know and to work with. We will treasure the time we spent with her.’