Auditors BDO and Mazars have been called out for the “unacceptable” quality of their work by the accounting watchdog.
The Financial Reporting Council (FRC) said there has been “some improvement” across the auditing sector amid heavy scrutiny following failings linked to the major collapses of firms such as Carillion.
FRC chief executive Sir John Thompson said its latest report highlighted that “consistent, long-term improvement” is still needed across the industry.
The FRC said the results of the inspections of BDO and Mazars audits “remain concerning” and outlined that it has developed specific supervisory firms in an effort to drive improvement.
Only half of Mazars’ eight audits were deemed of an acceptable quality.
The report also said that just seven of the 12 BDO audits inspected by officials were deemed good enough.
All five audits by fellow mid-tier firm Grant Thornton were deemed acceptable, although the firm was fined £1.3m by the FRC earlier this week over failings in audits for Sports Direct.
Meanwhile, KPMG, which was singled out as a particularly poor performer in last year’s report, “significantly improved” although the regulator said it will still closely monitor the firm’s progress.
Overall, 75 per cent of audits for all firms inspected by the watchdog were good or required limited improvement, rising from 71 per cent in the previous year.
Sir Jon Thompson said: “While it is encouraging to see some improvement in audit quality at the largest audit firms, consistent, long-term improvement is still required across the market.
“We will monitor closely the potentially negative impact on the public interest that the de-risking by firms of challenging audits may have on audit quality.
“The FRC will continue to build on our assertive supervisory approach to ensure firms are consistently delivering high quality audit which will drive increased choice and resilience in the market over time.”