More arguments are being made that whatever the presumed unfairness of the old system, the abolition of the UK's resident non-domicile regime is driving significant numbers of HNW and UHNW individuals from the UK, and by more than some had expected.

At least 10 per cent of the UK’s wealthy non-dom population have left the country following tighter tax rules under the UK government, a report authored by a former UK Treasury economist says.

The figures are based on an analysis of data from migration advisory firm Henley & Partners on the decline in London’s millionaire population in 2024. They appear in a study by Chris Walker, a former member of the government economic service and founder of consultancy Chamberlain Walker Economics. 

The report was commissioned by Andrew Barclay, an entrepreneur and policy fellow at the Onward think tank.

The report referred to a University of Warwick study that appears to have influenced the current government's thinking. 

"It seems reasonable that non-doms living in the UK for such a long time would have a strong attachment to the country and have developed strong ties, to the extent it would override tax considerations. The problem, however, is that the study then took this elasticity (and that of another relatively small non-dom group) and applied it to the whole of the non-dom population to infer that very few non-doms would depart from the UK if they were similarly taxed," the report said. "With new evidence emerging, it appears that the study was overly optimistic about this. Strong indications are that significant numbers of non-doms, particularly wealthier individuals, have either already left the UK or will leave soon."

"This is not a static situation either – other countries are changing their tax regimes to attract non-doms thinking of leaving the UK. Countries such as Italy and Greece have very attractive offers already," it said. 

Debate continues on whether a variety of changes introduced by the Labour government, elected last July, are contracting the tax base. Already – and partly following proposed moves by the former Conservative government – UK Chancellor of the Exchequer Rachel Reeves has abolished the resident non-domicile system, replacing it with a new residency model. The inheritance tax net has been widened, exposing non-doms’ overseas assets to a 40 per cent tax rate, far higher than in many other developed countries. 

The report adds to other commentaries from the likes of the Adam Smith Institute, the Centre for Economics and Business Research (see here and here, respectively) that the end of the non-dom system is driving HNW individuals abroad. This news service is hearing that many such for example, have relocated to places such as Dubai and Italy.