UK firms are not maintaining a consistently high standard of auditing and some work is falling short of expectations, according to the UK Financial Reporting Council (FRC) latest audit quality review.

The UK regulator has today released its Audit Quality Thematic Review: Engagement Quality Control Reviews, which analyses work performed by the engagement quality control reviewer ("EQCR") in the audit of financial statements.

The review for year ending April 2015 includes 78 audits from nine UK firms: BDO, Crowe Clark Whitehill, Deloitte, EY, Grant Thornton UK, KPMG, Mazars, PwC and RSM.

The FRC said it was pleased to find the EQC review had directly contributed to improving quality on a small number of audits.

However, it said that a tenth of audits analysed held weaknesses which EQC review process had not identified.

As such, the FRC highlights one firm that did not have sufficient experience in a specialist sector, such as a bank, ultimately limiting its ability to make important judgment calls.

Elsewhere 12 audits were identified as having insufficient evidence that the EQCR had performed an adequate and timely review.

At most firms, the FRC writes, evidence to assess the scope of EQC review may include notes or annotations that show areas in which the EQCR challenged the audit team, as well as highlighting audit issues challenged and resolved.

In contrast, the FRC says three audits had "clear evidence that the EQCR’s challenge" led to further audit work being performed, directly improving quality.

The review identified eligibility, objectivity, evidence of the EQC review, effectiveness of EQC reviews and assessing the effectiveness as responsibilities auditors should pay particular attention to based on the review’s findings.

"This report identifies a number of areas where the effectiveness of the EQC review, and the evidence of the EQCR’s challenge of key judgments made by the audit team, needs to be improved", the FRC added.

More can be done by firms to evaluate the effectiveness of the ERQC and, where appropriate, implement additional procedures, the review continued.

"The EQCR plays an important role in the quality control process on an audit and is key to safeguarding audit quality", FRC executive director at conduct division Paul George said.

"It is imperative that firms’ do more to evaluate the effectiveness of the EQC review and for firms to require EQCRs to obtain formal feedback on their performance."