The level of fines has increased fivefold since the pandemic, when HMRC only issued £1.98m in penalties to these companies, marking a major escalation in compliance checks in the last two years.

Transfer pricing and R&D relief claims were the top areas where HMRC tightened up enforcement activity, revealed analysis by BCLP, the international law firm.

Data obtained by BCLP under a Freedom of Information request showed that the number of CT compliance checks completed by HMRC’s wealthy and mid-sized business unit rose from 2,099 in 2020-21 to 4,506 in 2024-25.

Over the same period, the value of fines issued to mid-sized businesses with turnover between £10m to £200m, jumped from £1.98m to £16.35m last tax year, an eightfold increase over just five years.

T