She will lead its specialist charity team, following the recent retirement of Steve Cresswell.
Cresswell retired in April, following an accountancy career of nearly 44 years. Steve joined Thomas Westcott in 2008 and played a lead role in growing the firm’s charities and not for profit team across the South West.
Williams joined Thomas Westcott as a trainee in 2006 and qualified as a chartered accountant in 2012.
Thomas Westcott has more than 400 charity clients, ranging from small, local not for profits run entirely by trustees to large regional charities.
Williams said: “Steve has done an amazing job in establishing Thomas Westcott as a regional leader in advising the charity sector. I feel very proud to have been part of his team as it has grown. As the new head of charities and not for profit, I am excited to be able to take us forward to the next chapter.
“Working with charities is incredibly rewarding because I really feel we are making a difference. The work is incredibly varied and I especially enjoy being able to identify changes charities can make to grow their funds.”