The firm attributes its 8.6% revenue rise to £1.02bn to its “continued programme of investment” and its focus on serving mid-sized businesses.

Despite a dip in profit per equity partner (PEP) last year due to a £120 million investment, BDO saw a 12% jump in PEP to £681,000 this year. Operating profit also increased by 15% to £227m.

Newly appointed managing partner Mark Shaw emphasised the firm’s commitment to supporting the UK’s mid-sized businesses, which he described as the “economic engine” driving growth and employment. He said: “Their success, combined with the capabilities of our people, have led to our success.

“These businesses are frequently overlooked and undervalued. It is easy for policy makers to focus on large businesses who naturally have the profile to command attention, but businesses that are mid-market or smaller are a vital part of the UK’s growth story contributing £2.4 trillion of revenues to the economy and 61% of UK employment.”

“They are a huge segment of the economy and one that should be listened to.”

He also highlighted BDO’s dedication to diversity and inclusion. Mr Shaw added: “Our people have worked incredibly hard to build what has now become a £1bn firm.

“We remain committed to investing in first-class people and first-class infrastructure. The underlying strength of our firm and the talent of our 8,000 people have put us in a great position for the years ahead to work with businesses across the UK and more widely.

“Uncertainty in the UK and across global markets is likely to continue, and so we will not be complacent.”

He concluded: “As BDO’s new managing partner, I re-iterate our commitments on diversity and inclusion – including on gender balance, ethnicity and social mobility – and I fully support our programmes in these areas.

“As we look to the future, we have a clear strategy for balanced growth; growth which puts serving the public interest, doing the right thing, our culture and our people at its heart.”