Today, we have summarised the six major red flags that are most likely to trigger an HMRC tax investigation for both business owners and individual taxpayers.

Many UK business owners will already be aware of upcoming compliance changes. Companies House has confirmed that identity verification will soon be compulsory for company directors and persons with significant control (PSCs). This month, the agency officially announced the implementation date. From 18 November 2025, company directors and PSCs will be required to provide a personal code when filing registration documents.