IR35 take-home comparison
An Inside IR35 determination typically costs contractors 20-30% of net take-home. This tool quantifies that cost in £/day and shows the rate uplift you'd need to negotiate to stay whole.
Outside figures use the same optimiser logic as our Director Pay tool (own limited company with an optimised salary plus dividends). Inside figures calculate the umbrella / deemed-payment route with employer National Insurance oncosts stripped off the top. Built for UK contractors and IT consultants running through their own limited company.
Your Contract
What this changes
Headline contract day rate. Drives gross contract value (rate * days). Inside IR35 the deemed payment is taxed as employment income; Outside IR35 it lands in your Ltd company as fee income, then flows out via salary plus dividends.
What this changes
Billable days. Typical full-time after holidays and bank holidays is around 220-225. Lower days reduces gross income, dropping you down the income-tax bands, which usually narrows the gap between Inside and Outside.
What this changes
Inside IR35: pension salary-sacrificed pre-tax through the umbrella, sheltering income from PAYE plus NI. Outside IR35: company contribution that reduces taxable profit and Corporation Tax. Pension materially closes the Inside-Outside gap because Inside has no other shelter.
What this changes
Umbrella company's weekly fee for processing your Inside IR35 contract. Comes off the top before employer NI and tax are calculated. Typical range £15-£30/week. Has no effect on the Outside IR35 path.
What this changes
Inside IR35: Plans 1, 2, 4 and 5 repay at 9% above the plan threshold, and Postgraduate loans repay at 6%. Outside IR35 uses salary plus dividends drawn.
Annual delta (Outside, Inside)
Rates current for tax year 2026/27
These calculators are diagnostic tools intended to give you an initial estimate. They are not a substitute for personalised advice on your specific circumstances. Figures depend on the inputs you provide and on tax rules that change over time. Speak to us before acting on any result.
A CIMA Chartered Management Accountant will review your details and send you a tailored breakdown.
Inside figures assume umbrella processing: employer NI (15%) and umbrella margin are stripped from the assignment rate before PAYE applies. Outside figures assume a PSC with optimised salary and dividend extraction. Your specific day rate, umbrella provider and pension setup can shift these figures by £1k-£3k/yr.