The most recent available data for this slice of the population suggests that the decline in their number has decelerated as new rules enforced a few years ago have become embedded.

The number of non-domiciled UK residents slipped to 78,000 in the 2018/19 financial year from 78,700 a year before, suggesting that uncertainties over Brexit, as well as domestic politics at the time, did not greatly hit this population group. 

The figures are based on people claiming non-dom status in their tax returns and filed with HM Revenue & Customs. The slowdown in the recent decline of non-dom numbers shows that people have become used to legal changes to the system, HMRC said in a recent statement. 

The stakes are large: HMRC estimates that non-dom taxpayers paid £7.828 billion ($10.2 billion) in UK income tax, capital gains tax and National Insurance contributions in the 2018/19 financial year, rising from the preceding 12-month period, where they were estimated to have paid £7.571 billion.

"Although the figures released today by HMRC show a slight decrease on the previous year, as the figures represent a period of time in which the recent general election, Britain leaving the EU in January 2020 and COVID-19 had not yet played out. Those wanting to relocate because of the deemed domicile tax changes will have largely done so, and those that remain are likely taking a wait-and-see approach as the UK’s future direction crystallises,” Rebecca Fisher, partner in the private client team at law firm Russell-Cooke, said.

“It remains to be seen what the long-term outlook is for non-doms but almost certainly recent events and unprecedented government spending will require funding. Increased taxation will be high on the agenda, which has already been hinted at, with recent months seeing renewed talk of the introduction of a wealth tax. Whether this will be the year for sweeping tax reforms will only be known in the autumn when the Chancellor delivers the budget,” Fisher said. 

Tom Elliott, partner and head of London Private Clients at Crowe UK, the accountancy firm, said: “[The] non-dom stats indicate that the impact of changes made in 2017 has now stabilised. Looking at year-on-year movement, the number of non-dom taxpayers declined slightly from 78,700 to around 78,000, while the amount collected across income tax, capital gains and National Insurance contributions rose slightly to £7.828 million. The lack of significant fluctuations since the 2017 reforms shows that the UK remains a popular jurisdiction for mobile high net worth families.”