The NAO has issued its briefing examining the government’s processes for investigating complaints about employers not complying with national minimum wage regulations.

Since the government began enforcing the national minimum wage in April 1999, HMRC has identified £68 million in arrears for over 313,000 workers, according to the report. The number of workers identified as being owed arrears in 2015–16 was 58,000 compared to 26,000 in 2014–15.

The report outlines how HMRC has significantly reduced the average time taken to investigate complaints about employers’ non-compliance with the National Minimum Wage, but some complainants (469 or 17 per cent of the caseload) still have to wait over 240 days to get their cases resolved.

The time taken to investigate complaints varies considerably and depends on a number of factors such as the complexity of cases and the co-operation of the employer. Non-compliance with the national minimum wage in the social care sector remains a concern.

According to the NAO, there is no accurate overall measure of non-compliance with the national minimum wage regulations and, as a result, it has been difficult to assess the effectiveness of HMRC enforcement activities over time.