Know your tax. Keep more of it.
The UK's clearest calculator for contractors, freelancers, and directors. Sole trader, Ltd, umbrella, IR35 — calculated in real time. No jargon. Just your number.
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Real-time · shareable by URL · no sign-up
Sole Trader
Freelancers, consultants, self-employed
Ltd Director
Directors paying salary and dividends
Umbrella
Contractors working through an umbrella company
IR35 Checker
Not sure about your IR35 status? Find out.
Your salary
is nobody else's business.
Most tax calculators are lead-generation funnels. We're not. KnowMyTax runs entirely in your browser — there's no backend, no database, and no email field to hand over.
- Zero sign-up. No email, no phone, no "book a call" pop-up.
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- Shareable by URL. Inputs live in the link — send to your accountant, not to us.
- Open methodology. Every figure traces back to HMRC. Read the methodology .
⌥⌘I · NetworkThree steps. One honest number.
Drag a slider, switch structure, toggle IR35 — the take-home number updates as you type. No "Calculate" button. No server call.
Every scenario lives in the URL, so you can send the exact numbers to your accountant without us ever seeing them.
Pick your structure
Sole trader, Ltd director, or umbrella. Each has its own optimised flow.
Enter your numbers
Income, expenses, pension. The number updates as you type — no "Calculate" button.
Get your take-home
Full breakdown by band, with a shareable URL. Tweak any rate to model a Budget scenario.
The bits people ask twice.
What is IR35?
IR35 is the UK's set of off-payroll working rules. They decide whether a contractor working through an intermediary (usually a Ltd company) should be taxed as a deemed employee. "Inside IR35" means PAYE applies; "outside" means you can use the Ltd company's tax efficiency.
Check my IR35 status →What's a payment on account?
HMRC requires self-employed people to pay tax in advance for the next tax year — two equal payments due 31 January and 31 July, each based on half your prior year's bill. They count toward the next return, but you need the cash ready.
See your payments on account →Sole trader or Ltd company — which is better?
Sole trader is simpler — one tax return, no company filings. Ltd is more tax-efficient above ~£40-50k profit thanks to the salary/dividend split, but adds bookkeeping, Companies House filing, and corporation tax. The break-even varies year to year as rates change.
How much tax do I pay on dividends?
The first £500 (the dividend allowance) is tax-free. Above that: 10.75% basic rate, 35.75% higher rate, 39.35% additional rate (2026-27 rates — ordinary and upper rose 2pp from April 2026). Dividends sit on top of your other income in the bands.
See dividend tax in your situation →What's the optimal salary for a Ltd company director?
For 2026-27, almost always £12,570 — the personal allowance. It's fully corporation-tax-deductible, attracts no income tax or employee NI, and only triggers a small employer NI bill above the £5,000 secondary threshold. The remainder flows out as dividends.
See the optimised split → Your number
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No sign-up. No email. No sales call. Just a clear breakdown of what you keep.