Question to the HM Treasury:

To ask the Chancellor of the Exchequer, what estimate she has made of the number of high net worth individuals who have left the UK in each year since 2024.

There is no single agreed definition of a high net worth individual, and taxpayers are not always required to inform HM Revenue and Customs when they leave the UK. Some individuals may submit a P85 after leaving the UK if they are seeking a repayment of income tax, but this is not required in all cases.

Taxpayers within Self Assessment can indicate that they have become non‑resident. Self Assessment tax returns for the 2025–26 tax year are not due until 31 January 2027.

The reforms to the tax treatment of non-domiciled individuals have been specifically designed to make the UK competitive, with a modern, simple tax regime that is also fair. The introduction of a residence-based tax system is expected to raise £39.5bn by 2030-31 (as costed by the OBR last autumn), and the OBR have said that there is no firm evidence to change the estimated impact of the reforms on migration. As set out at Budget 2025, the Chancellor has been clear that she will continue to assess the regime to ensure it strikes the right balance, including on competitiveness.