Inside IR35 rate calculator
At £500 a day outside IR35, an umbrella assignment rate of £532.53 leaves you the same money a year, an uplift of 6.5% rather than the 15% to 20% agencies often quote. Enter your own outside rate, or switch direction to price an inside offer as an outside rate.
Rates for the 2026/27 tax year. Checked 7 November 2026.
About £535 a day to the nearest £5. That is a 6.5% uplift on the outside rate, less than the 15% to 20% agencies often quote (£575.00 to £600.00).
| Outside, Ltd | Inside, umbrella | |
|---|---|---|
| Day rate | £500.00 | £532.53 |
| Billed | £110,000.00 | £117,156.60 |
| Umbrella margin | — | − £1,100.00 |
| Employer NI | − £1,135.50 | − £14,419.69 |
| Apprenticeship levy | — | − £505.66 |
| Expenses | − £2,000.00 | — |
| Corporation tax | − £21,238.05 | — |
| Income tax | − £0.00 | − £28,110.50 |
| Employee NI | − £0.00 | − £4,033.23 |
| Dividend tax | − £16,638.93 | — |
| Take-home | £68,987.52 | £68,987.53 |
| A month | £5,749 | £5,749 |
IR35 status is a matter of fact about the contract and how you work, not a choice, so treat this as pricing the two outcomes only. The two take-homes can differ by under £1 because rates are matched to the penny. Inside figures assume holiday pay is rolled up and you opt out of the umbrella pension. Scottish income tax is not supported yet.
Worked example: £500 a day outside
Outside IR35, £500 a day over 220 days bills £110,000 through your limited company. After a £12,570 salary, £1,135.50 of employer NI and £2,000 of expenses, the company pays £21,238.05 of corporation tax. You pay £16,638.93 of dividend tax and keep £68,987.52.
Inside IR35 through an umbrella, an assignment rate of £532.53 a day bills £117,156.60. The £25 a week margin over 44 weeks takes £1,100, employer NI takes £14,419.69 and the apprenticeship levy takes £505.66, leaving gross pay of £101,131.26. Income tax of £28,110.50 and employee NI of £4,033.23 leave £68,987.53, a penny more than outside.
So the inside rate needs to be 6.5% higher, about £535 a day to the nearest £5, and that is your floor when you negotiate. A 15% to 20% uplift would be £575 to £600, which leaves you better off inside than out.
Why the result moves
Your day rate changes the uplift. At £400 a day the matching inside rate is £436.44, a 9.1% uplift. At £650 it is £700.55, or 7.8%. At £900 it is £914.85, only 1.6%. Each route crosses its tax thresholds at a different day rate, such as the higher rate from £50,270 and the loss of the personal allowance above £100,000, so the gap between them rises and falls.
Expenses and a company pension pull in opposite directions. Expenses raise outside take-home, so they push the inside rate up. A company pension is not counted as take-home, so a £10,000 pension at £500 a day brings the matching inside rate down to £487.74, below the outside rate. A lower umbrella margin lowers the inside rate a little: £15 a week instead of £25 saves about £2 a day.
When this calculator is wrong for you
- Your inside offer is a PAYE rate from the agency, not an assignment rate to an umbrella.
- You pay into a pension through the umbrella by salary sacrifice.
- You leave profit in the company instead of drawing it all as dividends.
- You have other income, a student loan or Child Benefit to repay.
- You live in Scotland.
Questions people ask
Why is the uplift smaller than people say?
The outside route pays tax too. At £500 a day the company pays £21,238.05 of corporation tax and you pay £16,638.93 of dividend tax, so an inside rate only 6.5% higher leaves the same money. Dividend tax went up in April 2026, which has narrowed the gap.
What do agencies mean by an uplift?
Usually the percentage added to an outside rate when a role is moved inside IR35, often quoted as 15% to 20%. Some agencies mean the extra needed to cover employer NI and the levy only. Ask which rate the figure applies to and whether it is an assignment rate paid to the umbrella.
Why does employer NI come off my rate?
The umbrella employs you, so it owes employer NI at 15% on your pay above £5,000 and the 0.5% apprenticeship levy. It pays both out of the assignment rate before your gross pay is set. At £532.53 a day that is £14,925.35 a year.
Can I negotiate the inside rate?
Yes. The rate is a commercial term between you, the agency and the client. Use the equivalent rate here as your floor and the rounded figure as a clean number to ask for.
Does an umbrella pension change the answer?
It is not modelled. Paying into a pension by salary sacrifice through the umbrella saves employer NI and income tax, so part of your inside pay goes further. If you plan to do that, the inside rate you need is a little lower than shown.
What about expenses?
Outside, your company deducts allowable expenses before corporation tax. Inside, travel and subsistence for the assignment are not allowed. With no expenses outside, the matching inside rate at £500 a day rises from £532.53 to £545.58.
How this is worked out
The calculator works out take-home on the rate you know, then searches for the rate on the other route that gives the same take-home. Outside: revenue less salary, employer NI, expenses and pension gives profit; corporation tax with marginal relief comes off; all that is left is paid as dividends and taxed above the salary. Inside: assignment income less the umbrella margin; employer NI at 15% above £5,000 and the 0.5% apprenticeship levy are solved out of what remains to give gross pay; income tax and employee NI then apply. The search halves a range from £0 to £10,000 a day 60 times and keeps the penny rate whose take-home lands closest. The uplift is the inside rate divided by the outside rate, less one.
Full formulas, rounding rules and test cases are on the methodology page. Every rate update is listed in the changelog.