Inside vs Outside IR35 in 2026: How Much More Do You Need to Charge to Break Even?

Hi Angela. We are unpacking "Inside vs Outside IR35 in 2026: How Much More Do You Need to Charge to Break Even?" today and tying it back to the wider Cost Saver ecosystem, including tools like IR35 Inside vs Outside Take-Home Calculator, so you can turn insights into action quickly.

Exactly. Treat this chat as a smart estimate only, not as professional financial guidance. Always check important details with official sources or a qualified expert before making any big decisions.

Thanks Angela, good to be back. And yeah, this is — it's one of those topics where people think they've got a handle on it, and then they get their first payslip and go... wait. Where did my money go?

Not at all.

Yeah, of course. So, IR35 is basically tax legislation that's trying to catch people who — the government thinks are effectively employees but are billing through a limited company to pay less tax. Outside IR35 means you're genuinely running your own company. You invoice the client, you pay yourself a salary and dividends. Inside IR35 means HMRC considers you to be, for tax purposes, essentially an employee. So you get taxed like one. Usually through an umbrella company.

Yeah, exactly. They employ you on paper, they receive the assignment rate from the agency, and then they run payroll. So all your tax, National Insurance, their own fees — all of that comes out before you see a penny.

It really does. And I think the — well, the thing that catches most people out is that phrase. Assignment rate. Because when an agency says, you know, 'we can offer you £550 a day inside IR35', most people think that's their day rate. It is not.

No. That's the total pot that the umbrella company receives. And then it has to cover — right, so first the umbrella takes its own weekly margin, then employer National Insurance, potentially the Apprenticeship Levy, and only then does the remainder become your gross pay. And then from that gross pay you've still got employee National Insurance and income tax to come out.

It's layers. [laughs] And each layer is kind of invisible if you're only looking at your payslip.

Yeah, this is the thing a lot of people haven't caught up with. The Autumn Budget 2024 raised employer National Insurance from 13.8% to 15%. But also — and this is the bit that's maybe even more painful — it cut the threshold at which employers start paying it. That dropped from £9,100 a year down to £5,000.

Exactly. Both changes came in April 2025. And because on an inside IR35 contract all of that employer NI comes out of your assignment rate — not from some separate pot the client has — it effectively means there's less left for you.

Often not, no. The old rules of thumb — you know, 'add 20% and you'll be fine' — those were already a bit rough, honestly, and post-April 2025 they're genuinely out of date for a lot of people.

So the headline figure that comes out of comparing inside versus outside in 2026 is roughly 25% to 38% uplift. But — and this is a big but — that range is for people who were running their limited company reasonably efficiently. If you had few expenses, no company pension, modest day rate, you might be at the lower end. If you were making employer pension contributions, claiming proper business costs, maybe leaving some profit in the company for later years — you'd be towards the higher end.

No. And honestly, for some people it'll be outside that range entirely. Because there are also worked examples — using more modest assumptions — where the uplift comes out narrower. Like, for a £400-a-day outside rate with a lean company setup, the break-even inside assignment rate works out at about £442 a day. That's roughly 11%.

Right, but those calculations assume no pension contributions, only £1,200 in annual company costs, all remaining profit taken as dividends. Change any of those assumptions and the number moves. Does that make sense?

Yeah. So for a £400-a-day outside rate, the break-even inside assignment rate is about £442. For £500 a day outside, it's about £540 inside — roughly 8% uplift. And for £600 a day outside, you're looking at about £672 inside — about 12%. All of those assume 220 billable days, a £30 weekly umbrella margin, and standard PAYE.

It does, and that's partly because of where your income sits relative to the tax bands. The higher you go, the more of each extra pound gets taxed at 40%. And there's the personal allowance taper once you're over £100,000 — that makes it even messier.

Yeah, so — the personal allowance is £12,570, the higher rate threshold is £50,270, the additional rate is £125,140. All frozen for the 2026 to 2027 tax year. And the reason that matters here is — any uplift you negotiate on an inside contract, that extra money is going to be taxed at your marginal rate. So if you're already a higher-rate taxpayer, roughly 40p in every extra pound you negotiate goes to the taxman.

Exactly. That's — I mean, that's the key insight. It's not a simple percentage sum. Every extra pound you win is taxed at the margin, so you need to ask for more than the headline gap suggests.

Yeah, so this is a rough sense-check for a higher-rate taxpayer. Out of every £100 of assignment rate, about £1 to £2 goes to the umbrella margin. Around £13 goes to employer National Insurance and the Apprenticeship Levy where it applies. Then roughly £35 to £36 goes in income tax and employee NI. And that leaves about £50 in your bank account.

Roughly half. And that's why a flat 'add 10%' doesn't come close to restoring your position. Because that extra 10% — at higher rate — you're keeping maybe 50p in the pound of it.

Never. That's the invisible deduction. It's gone before your gross pay is even calculated. So if you're only looking at your payslip, you will genuinely underestimate how much of your day rate disappeared on the way.