Lexington Wealth Management, based in Cirencester, marked the milestone with a garden party at Siddington House, the home of founder and chartered financial planner Warren Shute.
Guests included clients, professional connections and friends from across the region.
Mr Shute said: “The evening was incredibly special for us.
“Many of the people we’ve built relationships with over the years were there in the garden with us.”
The evening featured a prize draw in support of Bala Children’s Centre, a UK-based charity supporting a children’s school in Kenya.
Warren and his wife Nicky have supported the charity for more than 12 years.
Established to serve individuals and families seeking clarity and confidence in their financial decisions, Lexington has steadily grown over two decades.
Mr Shute said: “We feel incredibly fortunate to do the work we do, with the clients we have.
“The last 20 years have been a privilege, and we’re looking forward to the next chapter.”
The firm offers holistic financial planning and evidence-based investment advice to private clients.