HMRC investigations double additional tax from large businesses

10 Mar 2026

HMRC's large business directorate has doubled the amount of tax revenue it collects, according to the National Audit Office (NAO).

A hands-on approach to tax compliance for large businesses yielded £15.8 billion during 2024/25. That is double what the unit collected in 2021/22.

The large business directorate has a return on investment of £95 for every £1 spent on staff pay, which is four times higher than HMRC achieves across all taxpayers.

The tax gap for large businesses has steadily decreased over the long term, from £7.5 billion in 2005/066 to £5.8 billion in 2023/24.

Since 2006, HMRC has put 70 large businesses through its High Risk Corporates Programme, designed to tackle its most complex or riskiest cases. This has brought in more than £32 billion in extra tax. 

The NAO recommended that HMRC expands the hands-on approach with other businesses as well as improving its IT systems.

Gareth Davies, Head of the NAO, said: 'Through its large business directorate, HMRC has developed an efficient and effective approach to ensuring large businesses remain tax compliant. This has made a significant contribution to reducing the tax gap.

'HMRC should continue to explore whether this approach could usefully be extended to other complex and high-risk businesses.'