Somewhere in the last five months, a founder raising an EIS round watched their company's fundraising ceiling double in size, and a founder selling one watched their exit tax climb for the third year running.
Neither change came from Autumn Budget 2026.
Both already happened, and that's the trap sitting underneath every "what to expect" piece doing the rounds right now, since this Budget hasn't landed yet, but the last one is still quietly reshaping what founders pay, and the two are getting muddled in a way that could cost people real money if they act on the wrong one.
We think the confusion is worth clearing up before 28 October, because Autumn Budget 2026 arrives at an unusually loaded moment, and it won't be the last founders hear about it this year. It's the first Budget under a brand new Prime Minister and a brand new Chancellor of the Exchequer - Andy Burnham took office on 20 July 2026, and John Healey, a Treasury veteran from the 2002-07 era, was appointed the same day.
Neither had touched the tax dials before this Budget, and both have been careful to say almost nothing concrete about them since.
What Has Already Changed for UK Founders
So, here's what's actually real and not speculated, the Enterprise Investment Scheme and its VCT cousin got a genuine expansion this year, as annual fundraising caps doubled to £10 million (£20 million for knowledge-intensive companies), lifetime limits doubled to £24 million, and the gross-assets threshold rose to £30 million before investment.
Seed EIS was left untouched - still being £250,000 per company and still £200,000 per investor a year, but none of that came from the Budget we're about to get, it actually came from last year's, and simply took effect on 6 April 2026.
EIS Got Bigger While Exit Tax Went Up
Business Asset Disposal Relief moved the other way, the rate charged on a qualifying exit - the relief that matters most to a founder actually selling their company - rose to 18% on 6 April 2026, up from 14% the year before and 10% before that.
The £1 million lifetime limit hasn't moved, so the arithmetic is blunt, a £1 million qualifying gain that would have cost £140,000 in tax under the old rate now costs £180,000. Business Asset Disposal Relief has effectively lost half its original discount against standard Capital Gains Tax in under three years, and almost none of that story is about Autumn Budget 2026 either, so it’s already happened, already legislated, already the rate a founder selling this autumn will actually pay.
Employer National Insurance Is Already Higher
Employer National Insurance sits in the same already-confirmed bucket. The Class 1 Secondary National Insurance rate rose to 15%, and then the threshold at which employers start paying it dropped to £5,000 a year back in April 2025, and that threshold is now fixed until April 2031. The Employment Allowance still softens this for smaller teams, but for any founder running payroll, employer National Insurance is one of the highest and least visible costs in the business. It's worth being precise here: none of the credible reporting we've found points to a further rise specifically at Autumn Budget 2026.
The manifesto pledge covers the headline rates of income tax, VAT and National Insurance for "working people" and employer National Insurance has, in practice, sat just outside that promise before.
What Is Still Open at Autumn Budget 2026?
So what's still open?
Capital Gains Tax is the closest thing to a live wire, the proposal getting the most airtime would align CGT with income tax bands - 20%, 40%, potentially 45% - rather than the current 18%/24% split, and one UK research centre has estimated a broader package of CGT reform could raise something in the region of £14 billion a year.
That said, we'd flag some genuine uncertainty even here: one recent advisory note suggested the CGT-alignment chatter has quietened in the past fortnight, with pension tax relief and inheritance tax relief now getting more attention instead.
Nothing about Autumn Budget 2026 is settled enough to plan around yet.
R&D Tax Relief Is Still an Open Question
R&D tax relief is the other genuine open question, and arguably the more interesting one for founders outside London. The current regime, which is a merged R&D Expenditure Credit at 20%, with Enhanced R&D Intensive Support giving loss-making, R&D-heavy SMEs an effective cash benefit closer to 27% , has already been through one overhaul.
What's less settled is whether Burnham's push for regional devolution reshapes it further, tying relief more tightly to regional investment funds and universities outside the South East, where R&D spend and tax-credit take-up already lag. Nobody we've found is confidently predicting which of those paths the Chancellor takes, and we'd rather say that plainly than take random guesses.
The OBR Forecast Will Set the Limits
One thing worth holding onto through all of this is that the UK Office for Budget Responsibility publishes its full economic and fiscal forecast alongside the Budget itself, and that forecast which is not press speculation, is what actually constrains what Healey can afford to do on 28th October.
Whatever gets announced will sit inside whatever headroom the UK Office for Budget Responsibility says the government has against its own fiscal rules, that's a more reliable signal than any single rumour doing the rounds this week.
What Autumn Budget 2026 Will Actually Mean for Founders
We'd also gently push back on the idea that any of this determines whether people start companies in the first place. Founders we've come across in past reporting cycles tend to say the same thing after every Budget, so disappointing or not, the decision to build was never really priced against a future tax scenario.
What Autumn Budget 2026 will do is shape the economics of scaling and exiting a company that already exists which is, how much of an EIS round a company can raise, what an exit is actually worth after Business Asset Disposal Relief, and what a growing payroll costs once employer National Insurance is factored in.
The Question Still Hanging Over 28 October
So here's where we'll leave it, because we too don't know the answer: does Healey's Treasury reach for Capital Gains Tax as the headline revenue lever on 28 October, or does the pressure land somewhere quieter like pensions, thresholds, and R&D, all while CGT speculation turns out to have been louder than the actual outcome?
We'll be waiting and watching the UK Office for Budget Responsibility's forecast as closely as the speech itself to find out.
Also Read: ESG Reporting for Startups: What UK Founders Need to Track
Sources: Rathbones, 4 September 2026; Coutts, 21 August 2026; Grant Thornton, September 2026; Simply Business, 4 September 2026; gov.uk policy paper, 26 November 2025; Startups Magazine, 1 September 2026; BDO, September 2026; Saxo, 3 September 2026.
