UK statistics
UK ISA Millionaires 2026: How Many + How They Got There
HMRC data released to Rathbones under a Freedom of Information request show 5,070 people held ISAs worth £1 million or more at the start of the 2023/24 tax year. Rathbones projects that this could have risen to around 17,600 by April 2026, assuming 8% annual returns and full use of the annual ISA allowance.
Headline numbers
- UK ISA millionaires, April 2023
- 5,070 HMRC data via Rathbones FOI
- Projected ISA millionaires, April 2026
- 17,600 Rathbones, 8% returns + full allowance
- ISA millionaires in 2016
- 450 Rathbones series
The detail
The count of ISA millionaires is not part of HMRC's published ISA statistics. It comes from HMRC data that Rathbones obtained through a Freedom of Information request and published on 24 March 2026: at the start of the 2023/24 tax year (5 April 2023), 5,070 people held ISA portfolios worth £1 million or more. A further 1,210 held between £950,000 and £1 million, and 48,160 held between £500,000 and £750,000 (all rounded to the nearest 10).
Rathbones then projected the figure forward. Assuming 8% annual investment growth and full use of the £20,000 allowance each year, it estimates around 17,600 ISA millionaires by April 2026, more than three times the 2023 count. At 8% with no further contributions after April 2023 the estimate is almost 13,100. On a more cautious 5% return it is around 12,300 with full allowance use, or 9,300 with no further contributions. These are modelled projections, not counts.
Rathbones' own series shows how quickly the group has grown: 450 ISA millionaires in 2016, 740 in 2017, 1,190 in 2018, 2,000 in 2019, 1,480 in 2020, 4,070 in 2021, 4,850 in 2022 and 5,070 in 2023. The 2016 to 2023 rise is more than elevenfold. Rathbones says the number "has at least doubled every three years since 2016" and grew fastest when global equity returns were strong.
Rathbones attributes the growth to investment returns, compounding inside a tax-free wrapper and consistent use of the annual allowance over many years. Because the projection assumes uninterrupted saving and steady returns, the true April 2026 figure will only be known if HMRC releases updated data.
Sources
- Rathbones - ISA millionaires set to more than treble over three years (24 March 2026) (retrieved 2026-09-30)
- gov.uk - Individual Savings Accounts (ISAs): allowance (retrieved 2026-09-30)
- Our methodology & full source list →
Related statistics
- Top 1%
Being in the UK's top 1% of income earners requires total pre-tax income of roughly £207,000 per year (HMRC Personal Incomes Statistics, tax year 2023/24 - the most recent complete dataset).
- What Counts as Rich
There's no official "rich" threshold, but three proxies are commonly used: the top 1% of UK taxpayers by income (£207,000 or more, HMRC, 2023-24), the additional-rate tax band (above £125,140), or the wealthiest 10% of households in Great Britain (£1,200,500 or more, ONS).
- Pension pot needed
The Retirement Living Standards, published by Pensions UK, put the yearly cost of retirement for one person outside London at £13,900 (Minimum), £32,700 (Moderate) and £45,400 (Comfortable). Allowing for Income Tax and a full new State Pension, and drawing 4% a year, that implies a pot of about £630,000 for Moderate and £1,054,000 for Comfortable.