IR35 Changes 2026: What Actually Changed for Contractors

By Robert Marjoram, Director, Together Accounting | July 2026

Daniel runs a one-man cybersecurity contracting business from home near Norwich, invoicing a mid-sized engineering firm £450 a day, around £108,000 a year. In June 2026, a fellow contractor on an online forum told him something about the IR35 changes 2026 brought in that would have been an expensive mistake to believe.

The claim was simple and confident: any client with turnover under £15 million was now automatically “small,” so IR35 responsibility had shifted onto him, and he should start invoicing outside IR35 without waiting for a fresh Status Determination Statement. It sounded plausible. The £15 million figure is real. The date is real. What’s wrong is the conclusion, and it’s a mistake that’s already cost several contractor-press outlets a published correction.

If you’ve heard something similar this year, whether from a forum, a fellow contractor, or a generic guide, this article sets the record straight on what genuinely changed for UK contractors in April 2026, what hasn’t changed yet, and the one change that’s already live and needs your attention now. The figures below carry the argument. Read them in order.

The Headline Numbers

What’s actually happening in 2026-27:

• Small company thresholds for off-payroll working rose to £15 million turnover (from £10.2 million) and £7.5 million balance sheet (from £5.1 million), for financial years beginning on or after 6 April 2025
• HMRC’s own guidance confirms this threshold change has “no practical impact for OPW until 6 April 2027, at the earliest”
• For many end-clients, the realistic earliest date is 2028-29, not 2027-28
• Umbrella company joint and several liability rules genuinely did take effect on 6 April 2026, making agencies and end-clients liable for PAYE and National Insurance contributions an umbrella company fails to pay
• HMRC estimates umbrella companies engaged at least 700,000 workers in 2022-23, with at least 275,000 of those placed at some point with non-compliant providers, contributing to roughly £500 million in lost tax revenue

Here’s the thing nobody’s properly explaining: two genuinely separate changes make up the IR35 changes 2026 story, and contractor forums have merged them into one. Only one of them is live right now. Untangling the two matters, because getting this wrong in either direction, acting too early or ignoring it entirely, has real financial consequences.

The IR35 Threshold Change That Hasn’t Bitten Yet

Off-payroll working rules (what most people still call IR35, though technically that’s the older self-assessed version) determine who decides your employment status for tax purposes: you, or your end client. That distinction matters enormously, because if your client is “medium or large,” they’re responsible for issuing a Status Determination Statement and getting it right. If your client is “small,” responsibility reverts to your own personal service company, or PSC, under the original Chapter 8 rules from 2000.

The size test uses the same Companies Act 2006 thresholds that all UK limited companies use for their own accounts filing. Those thresholds rose by roughly 50% for financial years beginning on or after 6 April 2025, turnover from £10.2 million to £15 million, and balance sheet total from £5.1 million to £7.5 million. The employee threshold of 50 didn’t move. On paper, that’s a meaningful jump, and it genuinely does mean fewer companies will eventually count as “medium or large” for IR35 purposes.

But here’s what the forum posts and some of the early contractor-press coverage got wrong. A company doesn’t flip size status the moment its accounts show smaller numbers. It has to meet the new thresholds for two consecutive financial years, and even then the change only applies from a later tax year, once the filing deadline for that second qualifying year has passed. HMRC’s own Employer Bulletin is direct about the consequence: “the threshold changes will have no practical impact for OPW until 6 April 2027, at the earliest.”

That’s the fastest possible case, using a transitional provision that lets a company count a financial year that started before 6 April 2025 towards the two-year test. For a company relying only on financial years beginning on or after 6 April 2025, without that transitional shortcut, the earliest realistic change is 2028-29.

Table: When Does the IR35 Threshold Change Actually Bite?

That middle row is the one worth sitting with. If your end client has a standard financial year and hasn’t already been running a financial year that straddled 6 April 2025, their exit from the medium/large category almost certainly won’t land until the accounts covering 2027-28 or later have been filed. Don’t take a single universal date as gospel here. The exact tax year depends on your specific client’s financial year end and filing deadline, which is precisely why the size-check step in the action list below matters more than memorising a date.

The threshold change is real and the clock is running, but for most end-clients, nothing about their IR35 position changes before 2028-29. Acting today on this specific change is jumping the gun by at least a year.

Worked Example: Take a nine-partner Norwich solicitors’ practice with a 31 March year end, which has issued SDS documents for its contract paralegals since 2021 under the old, tighter thresholds. Its most recent filed accounts show turnover of £14.8 million and a balance sheet total of £6.9 million, both now under the new £15 million and £7.5 million limits. On the surface, that looks like an immediate exemption. It isn’t.

One qualifying year on its own achieves nothing. The rules require the same result for two consecutive financial years before status can change, and the change only takes effect from a later tax year once the second year’s filing deadline has passed. Based on HMRC’s own guidance, this practice can’t legally stop issuing SDS documents before the 2027-28 tax year at the earliest, and given its year end and filing pattern, 2028-29 is the more realistic date. A simple two-year tracking sheet, keyed to the December filing deadline, is the practical fix, and it works whether you’re the client or the contractor watching from the other side.

Government modelling from the Department for Business and Trade estimates that under the new thresholds, roughly 9,000 companies will move out of the “medium” band nationally, a genuine shift, just not an immediate one. If you’ve seen a bigger figure quoted elsewhere, treat it with caution. It doesn’t trace back to a primary government source.

Who Actually Determines Your IR35 Status Right Now?

While the threshold change plays out over the next couple of years, the existing rules for determining IR35 status haven’t moved an inch. The rules themselves didn’t change in April 2026, only the size thresholds that decide which rulebook applies to a given client. Here’s how it still works today.

If your end client is a public sector authority, or a medium or large private sector organisation, they’re responsible for determining your employment status and must issue a Status Determination Statement setting out their conclusion and the reasoning behind it. That statement has to go to both you and the agency or fee-payer in the chain. If the client fails to issue a valid SDS at all, the tax and National Insurance liability defaults to them, not you.

If your end client genuinely is small under the current thresholds, responsibility reverts to your own PSC under Chapter 8, the original 2000 intermediaries legislation. You self-assess whether you’re inside IR35 or outside IR35, and you carry the compliance risk if HMRC later disagrees. Chapter 8 never went away. It’s been running quietly alongside the newer client-led Chapter 10 regime the whole time, applying automatically whenever a client falls below the size thresholds.

If you disagree with an SDS, you can make representations to the client, who then has 45 days to respond, either upholding the original determination with reasons or issuing a new one. Miss that 45-day window and the liability that would otherwise sit with the fee-payer shifts to the client instead, until they comply. There’s also a formal mechanism, a client size information request, that lets you ask your end client to confirm its size classification in writing, with the same 45-day response window. Almost no contractor we speak to knows this exists, and it’s genuinely useful if you want certainty rather than guesswork.

That last point matters more than anything else in this article. There’s no statutory duty on an end-client to tell you proactively that its size classification is approaching, or has crossed, a threshold. Nobody sends you a letter. If you want to know where your client actually stands, you have to check, or ask.

Worked Example: Take Daniel’s situation from the opening. Before acting on forum advice, the sensible check is the end client’s last two sets of filed accounts at Companies House, freely available to anyone. In his case, that showed turnover of £16.8 million and a balance sheet total of £8.1 million for the most recent year, both comfortably above the new £15 million and £7.5 million limits. The client remains “medium,” the existing SDS still stands, and nothing about Daniel’s IR35 position changed at all.

Had he invoiced outside IR35 on the strength of a forum post, and had HMRC later disagreed, his PSC could have faced a full PAYE and National Insurance assessment on the entire £108,000 contract value, plus interest and penalties. A five-minute Companies House check is considerably cheaper than that outcome.

The IR35 Change That’s Actually Live: Umbrella Company Liability

While the threshold story is a slow burn, one part of the April 2026 changes is genuinely, immediately real, and it deserves more of your attention than it’s currently getting. From 6 April 2026, new joint and several liability rules apply to umbrella companies, inserted into ITEPA 2003 as a new Chapter 11 by the Finance Act 2026, which received Royal Assent on 18 March 2026.

Before this date, if an umbrella company failed to properly account for PAYE income tax, employee and employer National Insurance contributions, or the Apprenticeship Levy on a worker’s pay, HMRC’s recovery route ran through the umbrella company alone. From 6 April 2026, the agency holding the contract with the end client, or the end client itself if there’s no agency in the chain, is jointly and severally liable alongside the umbrella company for that shortfall. HMRC can pursue the full amount from any single liable party in the chain, who then has to recover a contribution from the others through civil proceedings if they want their money back. If the agency in the chain is based overseas, liability passes straight to the UK end client instead.

Table: Umbrella Company PAYE Liability, Before and After 6 April 2026

The practical effect: if you engage contractors through an umbrella company, or you’re a contractor placed by an agency through one, everyone in that chain now has skin in the game if the umbrella gets PAYE wrong. That’s a real incentive shift, not a paper one.

Worked Example: Consider a Norwich-based recruitment agency placing six contract engineers with a local manufacturing client via an umbrella company. One of the six, a controls engineer, is paid £1,200 a week, £62,400 a year. Properly calculated, employer National Insurance on that pay should be 15% of earnings above the £5,000 secondary threshold: 15% of £57,400 comes to £8,610 a year, the kind of figure we break down in full in the true cost of employing someone in the UK. Due diligence on the umbrella provider ahead of the 6 April 2026 start date found only around £2,000 had actually been remitted for this worker, a shortfall of £6,610. Extrapolated across all six placements on broadly similar pay, the agency’s potential joint and several exposure once the new rules bit was in the region of £39,660.

The practical fix in a case like this is straightforward: move the placements to a properly compliant umbrella provider before the liability rules take effect, and put a quarterly PAYE reconciliation check in place with any umbrella used going forward, so a shortfall like this can’t build up unnoticed again.

If you’re a contractor rather than an agency, the same warning applies in reverse. A take-home percentage that sounds too good against your assignment rate, well above the 60-70% that’s typically left once PAYE, employee and employer NIC, the Apprenticeship Levy and the umbrella’s own margin are properly deducted (that’s a rule of thumb, not an official HMRC figure), usually means something’s being avoided somewhere in the chain. Even though the direct legal exposure under the new rules sits with the agency and end client rather than you personally, using a provider like that puts your assignment and your relationship with the end client at real risk the moment HMRC intervenes. Sticking with an established, properly PAYE-compliant umbrella is the boring, correct answer.

What the IR35 Changes 2026 Mean for Your Contracting Business

None of this means your contracting business is exposed to some new, immediate IR35 risk you didn’t have last year. It means two different things are true at once, and treating the IR35 changes 2026 as one story is where the risk actually lives.

Worth saying separately: the decisions that shape how much you actually keep from your contracting income, your salary and dividend strategy and keeping your director’s loan account clear of the S455 charge, don’t depend on any of this. They’re worth reviewing on their own timetable, IR35 status aside.

The threshold change is real, the clock on it is already running, and it will eventually matter for a meaningful number of end-clients. But acting today as though your status has already changed, based on a client’s current turnover alone, is jumping the gun by at least a year and potentially three. Equally, ignoring it completely means you’ll be caught flat-footed when your specific client’s qualifying years do complete, whether that’s 2027-28 or 2028-29.

The umbrella JSL rules are the opposite. They’re not building towards something. They’re live now, in this tax year, and they change who HMRC comes after if something in your labour supply chain goes wrong. If you’re a contractor working through an umbrella, or an agency or end client placing workers through one, this is the part of the 2026 changes that genuinely needs a decision this year, not a watching brief.

What to Do Now

1. Check your end client’s last two filed sets of accounts at Companies House. This is free and takes minutes. If turnover and balance sheet total both sit above £15 million and £7.5 million, nothing has changed for your IR35 status. If both figures have dropped below the new thresholds, don’t assume anything yet, move to step two.
2. If your client looks like it might qualify as small, use the formal client size information request instead of guessing. You have the right to ask, in writing, and your client has 45 days to confirm. HMRC provides a suggested template. This removes the guesswork entirely and creates a paper trail if HMRC ever questions your position.
3. If you engage contractors through an agency and an umbrella company sits in the chain, review that umbrella provider’s compliance before your next pay run. Ask for evidence of PAYE and National Insurance remitted for named workers, not just a general compliance statement. The joint and several liability rules mean you now carry genuine financial exposure if that provider gets it wrong.
4. If you’re a contractor being offered an unusually high take-home percentage through an umbrella, treat it as a red flag rather than good news. Ask specifically how PAYE, employee and employer NIC, and the Apprenticeship Levy are calculated on your rate. If the numbers don’t add up, walk away before your assignment does.
5. Build a simple tracking note against your own or your client’s financial year end, so you know exactly which tax year the threshold change could realistically affect your engagement, rather than relying on a headline date that may not apply to your specific situation.
6. Don’t change your invoicing basis, inside IR35 or outside IR35, on the strength of a forum post, a generic guide, or a client’s current turnover figure alone. Get your accountant to check the actual filed numbers and the two-year mechanics before you act.

Frequently Asked Questions

Do the IR35 rules themselves change in 2026?

No. The core off-payroll working rules, who’s responsible for determining status, how a Status Determination Statement works, and the consequences of getting it wrong, haven’t changed. What changed is the size threshold used to decide whether a client counts as medium/large (client-led Chapter 10) or small (contractor-led Chapter 8), and that change doesn’t produce a practical effect for any client until 2027-28 at the earliest.

Can I challenge a Status Determination Statement I disagree with?

Yes. You can make representations directly to the client, who then has 45 days to respond, either confirming the original SDS with reasons or issuing a revised one. If the client misses that deadline, the liability that would normally sit with the fee-payer shifts to the client instead, until they sort it out. This process sits alongside HMRC’s Check Employment Status for Tax tool, which remains the standard free way to assess a working arrangement, provided the information going in is accurate.

Does IR35 apply to sole traders?

Off-payroll working rules apply specifically to individuals providing services through an intermediary, typically a personal service company or limited company, rather than trading directly as a sole trader. If you invoice as a sole trader with no intermediary in the chain, the off-payroll working rules as described here don’t apply to you in the same way, though HMRC will still look at the underlying working practice to determine genuine self-employment status for other tax purposes.