Autumn Budget 2026: What’s Already Settled for Your ISA

The Autumn Budget is on 28 October 2026, and the biggest ISA changes are already settled: from 6 April 2027 the cash ISA limit falls to £12,000 for under-65s, cash held in a stocks and shares ISA picks up a 22% charge on its interest, and the overall £20,000 allowance stays where it is. The Budget could add to that list. At the time of writing, nothing more about ISAs has been announced.

What’s already decided

All at the time of writing, from the government’s own documents on gov.uk. Check there for the current position.

What’s already settled for ISAs?

Most of it was announced in the November 2025 Budget, and the detail has been filling in since. On 17 September 2026 HMRC published its formal impact note for the cash ISA changes, confirming they take effect on 6 April 2027. The regulations that make them law were still to be made at the time of writing, but HMRC has told Parliament they’re coming shortly and the figures haven’t moved.

For anyone investing rather than saving, the change that matters most is the 22% charge. It applies to interest on uninvested cash sitting in a stocks and shares ISA, not to shares, funds or dividends, and your provider pays it, so there’s still nothing to declare. I explain it in full in the 22% charge on cash in your stocks and shares ISA.

Two other dates sit alongside it. Also from 6 April 2027, unused pension pots count towards your estate for inheritance tax, which changes how an ISA and a pension compare as things to pass on. And the Lifetime ISA is due to be replaced by a new First-Time Buyer ISA, expected from April 2028. That consultation closed on 18 August 2026, and the government’s response is still awaited.

What could still change on 28 October?

Nothing about ISAs has been announced for this Budget. The weeks before any Budget fill up with guesses, and most of them turn out wrong. The only reliable information is what the Chancellor says on the day and the documents published on gov.uk straight afterwards.

These are the four things I’ll be watching.

The £20,000 allowance.
It has been held, not cut, and how the ISA allowance works hasn’t changed. Any move would be announced on the day.

The final shape of the April 2027 rules.
Especially how money market funds are treated inside a stocks and shares ISA, which matters to anyone planning to hold cash-like investments there.

The Lifetime ISA’s replacement.
The consultation response could come with the Budget or separately. Until it does, the Lifetime ISA carries on under its current rules.

Tax outside the wrapper.
Any change to dividend tax, capital gains tax or the allowances that go with them changes how much an ISA is worth. The higher tax is outside, the more the shelter saves, as I set out in do you pay tax on an ISA.

Should I do anything before the Budget?
Acting on a rumour is how people get caught out. Before the 2024 Budget, speculation about pension tax-free cash led some people to take money out early, and the change never came. Decisions made on what has actually been announced tend to age better. This is general information, not advice about your own situation.

I’ll update this article after 28 October with what actually changed. If you’d like it in your inbox instead, the monthly newsletter covers it, and signing up gets you my free ISA Starter guide. The whole method sits in the book.

When is the Autumn Budget 2026?
Wednesday 28 October 2026. HM Treasury confirmed the date in July.

Is the £20,000 ISA allowance changing?
Not as things stand. The government has said the overall £20,000 limit stays, with the cash part capped at £12,000 for under-65s from April 2027.

Can I still put £20,000 into a cash ISA this tax year?
Yes. The £12,000 cash limit starts on 6 April 2027, so the current tax year, which runs to 5 April 2027, is under the existing rules. If you’re weighing cash against investing, cash ISA vs stocks and shares ISA sets out the difference.

Is the Lifetime ISA closing?
It’s due to be replaced by a First-Time Buyer ISA, expected from April 2028. Existing holders are expected to keep paying in under the current rules, and the detail depends on the consultation response.

Where do I find out what actually changed?
On gov.uk, where the Budget documents are published on the day. I’ll also update this article once they’re out.