11 December 2025

Non-Big Four firms increase share of UK PIE audit engagements

Audit firms outside of the ‘Big Four’ have increased their market share of audit engagements on UK Public Interest Entities (PIEs) from 22% to 40% in 2024, according to a review by the UK Financial Reporting Council (FRC).

In that timeframe, non-Big Four firms also increased their market share of FTSE 350 audit engagements from 6% to 13%.

However, the FRC also found that the Big Four continue to “dominate the market in terms of audit fees”, earning 98% FTSE 350 audit fees and 91% PIE audit fees collectively in 2024.

 

Full report