Contractors IR35

How much will an IR35 tribunal cost?

It’s now well over a month since the IR35 reforms came into effect, shifting the liability of your IR35 status from you as the contractor to your fee-payer. But what exactly does…

Kingsbridge by Kingsbridge

It’s now well over a month since the IR35 reforms came into effect, shifting the liability of your IR35 status from you as the contractor to your fee-payer. But what exactly does that mean for you? And what costs would you be subject to if you are still liable for your IR35 status?

We take a look at this, and what happens if you want to appeal a decision made by HMRC.

Who is liable for IR35 costs?

Now that the IR35 reforms are here, the liability for paying the correct taxes and national insurance payments has shifted from you as a limited company contractor to your fee-payer. It is up to your client to determine whether you are inside or outside IR35, and this result is then passed down until it reaches your fee-payer.

If you are deemed inside IR35 by your client, then you will be subject to the same national insurance and tax payments as if you were an employee of the company. In this eventuality, your fee-payer would need to deduct these payments from your payslip.

If your end client does not fulfil their duty and provide you with an inside or outside determination, then if HMRC do come knocking, it would be your end client who would be subject to any fees and charges owed.

Equally, if your fee-payer has received an inside IR35 status determination and not acted on this, then they would then become responsible for the charges owed.

When are contractors liable for IR35?

It’s worth noting that there are a few instances when you as the contractor are still responsible for assessing your IR35 status. One example is if you are working for a small company, as deemed by HMRC.

HMRC’s definition of a small company is that at least two of the following must apply:

  • a turnover of £10.2 million or less;
  • £5.1 million or less on its balance sheet;
  • 50 employees or less.

Furthermore, if you are working for an overseas end client with no links to the UK, then the responsibility for your IR35 would remain with you. You can find out more about how IR35 applies when working outside the UK here.

What above previous years of IR35?

If you had previously declared yourself as outside IR35, but have now been assessed as inside IR35, HMRC have said that they would not use this change as a trigger to investigate you.

However, if they believe that you have committed fraudulent or criminal behaviour, or have legitimate cause to investigate you, then they will do so.

What if HMRC do investigate?

If HMRC investigates you and believe that you should have been inside IR35 when you have placed yourself outside IR35, then the first step is that HMRC will demand the retrospective PAYE tax and NI, plus any interest and penalties owed.

As of the 6th April 2021, the liability for these charges would sit with your end client or fee payer.

However, if HMRC are investigating a decision that was made before the IR35 reforms, or if you are still responsible for your IR35 status (for example working for a small company), then the liability for any charges would be yours to bear.

What if I want to appeal an IR35 decision?

If you do not agree with a decision that HMRC has given you, then the next step would be a first-tier-tribunal. This can be lengthy process, and you would need to account for the cost of legal defence costs, unless you are backed by an insurance policy.

How can I protect myself from IR35 costs?

To protect yourself from IR35 costs, you could look at IR35 insurance. One option is Kingsbridge’s IR35 Protect insurance.

Protecting everyone in the supply chain, the insurance will cover whoever is deemed liable by HMRC; whether that is you, your end client or fee-payer. This all-encompassing cover can also make you a more desirable hire, as it mitigates the risk to your agency and client.

Cover includes up to £100,000 of unpaid tax, interest and penalties enforced by HMRC, as well as IR35 status enquiry defence costs, up to £100,000. Plus, with IR35 protect premium, you get unlimited access to our award-winning status determination tool.

Get a quote today by clicking below or give our helpful team a call on 01242 808 740.

Related topics

Contractors IR35

You might also like...

Back to resources
Close up photo of female worker at a desk with laptop and calculator, representing article on what insurance contractors need
Contractor Guides Contractors 03 Nov 2026

What insurance contractors need?

We know it can be a minefield for contractors when it comes to purchasing the right contractor insurance to protect…

Image of a handheld drill on a work bench, representing guide on how to insure work tools for tradespeople
Trades Trades Life 09 Sep 2026

How to insure your tools: a tradesperson’s guide

Most tradespeople spend a lot of time thinking about the next job, the next customer, or the next challenge on…

A flat lay of a desk with stationery and notebook with writing 'insurance checklist', representing guide on questions to ask when buying contractor insurance
Contractor Guides Contractors 24 Aug 2026

7 things to ask before buying contractor insurance

Buying contractor insurance isn’t exactly the most exciting item on your to-do list.  When you’re focused on winning contracts, meeting…

Image of tradesman leaning against white van looking at insurance quotes on his phone, representing article discussing cheap tradesmen insurance
Trades Trades Life 28 Jul 2026

Cheap trades insurance: how low is too low?

When you’re running your own trades business, it’s only natural to try and keep costs to a minimum. But for…

Photo of protest crowd in london, representing article on loan charge review scandal
Contractors News 15 Jul 2026

Why the Loan Charge scandal isn’t going away

In the late 1990s, loan-based remuneration schemes began to emerge before becoming widespread among contractors and freelancers during the 2000s.…

Image of tradesman's arm being bandaged, representing article on employers' liability insurance for tradespeople
Trades Trades Life 07 Jul 2026

Do tradesmen need employers’ liability insurance?

If you’re a tradesman running your own business, you might assume employers’ liability insurance only applies to corporate companies. But…

Contractors News 19 Jun 2026

The tax, pension and savings changes UK contractors need to keep on top of

The 2026/27 tax year might not be bringing one dramatic overhaul, but it marks the beginning of a multi-year shift…

Photo of dug out earth with construction worker on mini excavator, representing article on plant and machinery insurance
Trades Trades Life 01 Jun 2026

What is plant and machinery insurance?

From diggers and dumpers to cement mixers and compressors, plant and machinery are the backbone of many trades. Whether you’re…

Close-up of dates on a green calendar, representing article discussing claims made vs claims occurring in business insurance
Contractor Guides Contractors 26 May 2026

Simplifying insurance: what is claims made vs claims occurring

When you’re choosing insurance, you’ll often come across two terms: claims made and claims occurring. They both refer to the…

Tradesmen tools laid out on table, representing article on tool theft stories and keeping tools safe
Trades Trades Life 20 May 2026

Tool theft stories: tradespeople going beyond locks to keep tools safe

As tool theft continues to dominate headlines and social feeds, many tradespeople are no longer relying on standard security –…

Goodie bag from Powered Now Advice on Tap event, representing article on tradespeoples' concerns about tool insurance claims
Trades Trades Life 15 May 2026

Powered Now ‘Advice on Tap’: trade talk and tool theft troubles

Powered Now’s landmark event brings together tradespeople of all backgrounds. But conversations highlight the ongoing issue of tool theft, the…

Photo of builders discussing construction plans, representing article on what professional indemnity means for tradespeople
Trades Trades Life 28 Apr 2026

What is professional indemnity for tradespeople?

Many tradesmen assume professional indemnity is only for people with a desk job. But in reality, if your work involves…

Image of two builders carrying construction materials, representing article on do subcontrctors need their own insurance
Trades Trades Life 15 Apr 2026

Do subcontractors need their own insurance?

Knowing whether subcontractors need their own insurance can be confusing. Whether working in construction, roofing, plumbing, electrical work or specialist…

Image of construction hard hats representing a guide to what insurance a tradesman needs
Trades Trades Life 31 Mar 2026

What insurance does a tradesman need?

Insurance sounds like a good idea, but how do you know what insurance you need as a tradesman? No two…

Photo of a presentation screen at an event held by Kingsbridge on the JSL legislation and what it means for recruitment agencies
Partner News Partners 30 Mar 2026

What JSL will mean for you: Five lessons from our expert panel

Earlier this month Kingsbridge brought together a panel of industry experts to discuss the implications of the government’s new JSL…

Builder working on a house extension roof, representing a guide to contract works insurance for tradespeople including what it covers
Trades Trades Life 17 Mar 2026

What is contract works insurance?

However big or small your construction project is, contract works insurance could be a lifesaver if something happens. When you’re…

Image of bricklaying representing article on who needs trades insurance and what it covers
Trades Trades Life 10 Mar 2026

Who needs trades insurance?

If you work in the trades, chances are you’ve already heard people chatting about tradesman insurance, but have been left…

Calendar with date circled, representing guide on what a retroactive date is in professional indemnity insurance
Contractor Guides Contractors 26 Feb 2026

Professional indemnity insurance: what’s a retroactive date

Whether you’ve just taken out a professional indemnity policy or you’re shopping for new business insurance, chances are you’ve come…

HMRC Making Tax Digital campaign asset, representing article disucssing the upcoming changes for sole traders April 2026
Contractor Guides Contractors 16 Feb 2026

A ‘Making Tax Digital’ wake-up call for sole traders

The way Britain pays tax is entering its biggest modernisation in a generation, with Making Tax Digital (MTD) for Income…

Photo of HMRC London offices representing article discussing the Employment Rights Act 2025 being law, what changes it brings and what businesses need to do now
Partner News Partners 22 Jan 2026

Employment Rights Act 2025 ‘brings world of work into 21st century’

Big changes to the world of work have been on the horizon for a while and the Royal Assent of…

HMRC Self Assessment tax return letter for 2025 tax year sent to UK taxpayer with UTR and NINO
Contractor Guides Contractors 16 Jan 2026

Online Self Assessment tax return deadline: what to know for 2026 (and beyond)

If you’re required to file a Self Assessment tax return for the 2024/25 tax year, the deadline to submit it…

Contractor Guides Contractors 01 Jan 2026

What is the difference between a sole trader and a limited company?

One of the big questions for any contractor when they first set up as self-employed is whether you should operate as a…

Image of sparks caused by power tools, representing article on what makes a trade high risk for insurance
Trades Trades Life 18 Dec 2025

Trades cover: who’s considered high risk for insurance

If you’re in the trades, you already know the job isn’t without its risks. But did you know those risks…