One question decides most of your money

Inside or outside IR35 changes your take-home by tens of thousands on the same day rate. It turns on how the work is really done, and it is worth checking before you sign rather than after.

What you get
  • Contracts and working practices reviewed
  • The salary and dividend split recalculated each April
  • Every company deadline tracked
  • The 24-month travel clock watched
  • Your exit planned a year ahead
  • One fixed monthly fee
See your monthly fee

Four figures worth knowing by heart

Four things govern a contractor's position, and the first one governs the other three.

IR35The end client decides, unless they are small
24 monthsWhen travel to a client site stops being allowable
15%Employer's NI, taken off an inside-IR35 rate first
9m + 1dAfter your year end, corporation tax is due

2026/27 figures. See key tax dates and the calculators for the full picture.

Two calendars running at once

A contractor has a company year and a personal tax year, and they do not line up. Missing that is how a good year turns into two bills in the same month.

Your year endWhatever date the company uses. Everything company-side hangs off it.
+9 months, 1 dayCorporation tax due.
+9 monthsAccounts at Companies House.
+12 monthsCT600 at HMRC.
31 JanuaryYour own Self Assessment, which a contractor almost always needs.
Every renewalStatus re-examined. It attaches to the engagement.

Source: gov.uk off-payroll working, Corporation Tax and Self Assessment guidance, checked July 2026.

Inside or outside IR35

If you contract through your own company for a medium or large end client, that client decides your status and has to give you a Status Determination Statement saying why. If the end client is small, the decision stays with your company — and so does the liability if it turns out to be wrong.

The test is about how the work is really done: control, whether you could genuinely send a substitute, and whether there is an obligation on both sides to offer and accept work. What the contract calls you matters much less than what actually happens on the engagement.

Inside IR35 the money is taxed like employment before it reaches you, and the limited company is doing very little for you. Outside, it does a great deal. That is why it is worth having a contract reviewed before you sign it rather than after HMRC asks.

Five, and the last one is the expensive one

Assuming last year's determination still holds
Status attaches to the engagement. A renewal with different working practices can be a different answer, and an extension is exactly when nobody re-examines it.
A right of substitution nobody would accept
A substitution clause is evidence only if the client would actually take a substitute. If everyone involved knows they would not, the clause is decoration and it will be read that way.
Travel claimed past the 24-month rule
Travel to a client site stops being allowable once you know the engagement there will exceed 24 months — from the date you know, which is usually earlier than the date you pass it. Extensions are what catch people.
The salary set once and left
The efficient salary moves with the National Insurance thresholds, and a one-person company cannot claim the employment allowance. Worth recalculating every April rather than repeating.
Closing the company badly
At the end of a contracting run, how the company is wound up decides whether the reserves come out as dividends or as a capital gain, potentially with Business Asset Disposal Relief. It needs planning a year ahead, and getting it wrong is the single most expensive avoidable mistake in contracting.

On the same assignment rate

A £110,000 assignment rate, inside IR35

A £500 day rate over 220 days, paid through an agency to your own company, with the engagement determined inside IR35. The employer’s National Insurance comes out of the assignment rate before anything reaches you — which is the part most people have not priced in.

Assignment rate
£110,000
Employer’s National Insurance at 15%, taken off first
−£14,348
Deemed employment payment — the taxable figure
£95,652
Income tax — 20% on £37,700, then 40% on £45,382
−£25,693
Employee National Insurance — 8% then 2%
−£3,924
Take-home
£66,036

Roughly 60% of the assignment rate, and £14,348 of it disappeared before the payslip was even produced. The number to negotiate on is what you keep. An inside engagement needs a materially higher day rate to match an outside one.

Worked through at 2026/27 rates from our own calculators, which follow gov.uk guidance checked in July 2026. An example. Your figures will differ.

The whole contracting position

Contracts reviewed before you sign

The written terms and the working practices, because HMRC looks at both and only one of them is in the file.

The salary and dividend split

Recalculated each April against the current thresholds rather than carried forward.

Every company deadline

Accounts, CT600, VAT, the confirmation statement and your own Self Assessment, all tracked in one place.

The 24-month clock

Watched on every engagement, so travel stops being claimed at the right moment rather than the convenient one.

The exit, planned early

Strike-off or liquidation, modelled a year ahead, so the reserves come out the cheaper way.

Somebody who knows contracting

Not a generalist meeting IR35 for the first time on your file.

What people ask us

How much does a contractor accountant cost?

You get a fixed monthly figure in writing after a 30-minute discovery call, priced on how the company is set up rather than on your day rate. A single-director company on one outside-IR35 contract is a different job from one running VAT, a second fee-earner and a director's loan. FreeAgent is included, worth up to £330 a year, and asking a question does not generate a bill — which matters on contract work, because the decisions that cost money happen mid-engagement rather than at year end.

Who decides whether I am inside or outside IR35?

It depends on the client. For every public sector client, and for medium and large private sector clients, the client decides and must give you a Status Determination Statement setting out the conclusion and its reasons. You can challenge it, and the client has to respond. Where the client is small, the decision stays with your own company under the older rules. A private sector client counts as small unless it exceeds at least two of three limits — turnover above £10.2 million, balance sheet total above £5.1 million, or more than 50 employees. If the client is anywhere near that line, ask them to confirm their size in writing; they are obliged to.

What actually changes if a contract is inside IR35?

Income Tax and employee National Insurance come off the fee at source, broadly as though you were employed by the client, and there is no dividend route on that income. Your company carries on existing for everything else — it can still hold outside-IR35 work, other clients, and its own assets. Status is decided engagement by engagement, so you can genuinely hold three contracts at the same time and have them land differently. What inside IR35 is not is a reason to close the company on its own.

Can I claim travel from home to the client's site?

On an outside-IR35 engagement, yes, while the site is still a temporary workplace. It stops being one — and the journey becomes ordinary commuting you cannot claim — once you expect to spend 40% or more of your working time there over a period lasting more than 24 months. The test bites from the moment you expect to pass it, so a 12-month contract extended to 30 changes the treatment from the date of the extension. On an inside-IR35 engagement the rules treat it as a separate employment, so home-to-site travel is not deductible at all.

Limited company or umbrella — which should I use?

It follows the work rather than the other way round. If your contracts are genuinely outside IR35, your own company usually leaves you better off and gives you control over timing, pension contributions and how profit is drawn. If everything you can get is inside IR35, an umbrella removes the running costs and filings of a company you are no longer getting much from. Most contractors sit somewhere in between and the answer changes year to year, which is the argument for reviewing it annually rather than deciding once.

What changed for umbrella company workers in April 2026?

From 6 April 2026 the responsibility for operating PAYE on umbrella company pay moved to the recruitment agency that contracts with the end client, or to the end client itself where there is no agency in the chain. The umbrella is still your legal employer and your employment rights are unchanged — what changed is who HMRC pursues if the tax is not paid over, and agencies now carry that liability. In practice it should make the mini-umbrella and disguised-remuneration schemes that caught contractors out much harder to run.

Do I still need a limited company if every contract is inside IR35?

Not necessarily, and that is worth a proper look. A company with no outside work still costs you accounts, a Corporation Tax return, a confirmation statement and the admin around them, in exchange for benefits you are no longer getting. Closing it is not free either — there may be retained profit to extract, and how that is done makes a real difference to the tax. If you expect outside-IR35 work to come back within a year or two, keeping the company dormant is usually cheaper than closing and re-forming.

Can I switch accountants in the middle of a contract?

Yes, at any point in the year. You tell us to go ahead, we write to your current accountant for professional clearance and your records, register as your agent with HMRC and set up the software while we wait. Most handovers finish inside a couple of weeks and the delay is almost always the other firm's reply. Two things to check at your end: the notice period in your existing engagement letter, and whether work you have already paid for has actually been done. You do not have to make the awkward call.

See what it would cost you

Four questions, the monthly fee on the screen and the full proposal in your inbox. No call needed unless you want one.

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