IR35 has been one of the most debated tax rules in the UK for over two decades. Whether you are a contractor, freelancer, or business owner, it affects the way you work and how much tax you pay. Understanding IR35 is essential if you want to stay compliant and protect your income.
In this article, we will explain what IR35 is, how it works, who it applies to, and what the latest reforms mean for you. You will also discover how to tell if you are inside or outside IR35, what red flags to avoid, and whether the rules could be scrapped in 2025.
What is IR35?
IR35, also known as the off-payroll working rules, is a piece of tax legislation that came into effect in April 2000. It was introduced to tackle disguised employment, a practice where individuals work as contractors through their own limited company but operate in a way similar to employees.
The aim of IR35 is simple: to ensure that workers who would be classed as employees if they were directly engaged by a business pay broadly the same Income Tax and National Insurance Contributions (NICs) as regular employees.
In short:
- If you are inside IR35, you are taxed like an employee.
- If you are outside IR35, you are recognised as genuinely self-employed and can take advantage of the tax efficiencies of working through your limited company.
This is why IR35 matters so much. It directly impacts how much money contractors take home and how businesses manage compliance.
IR35 Legislation: A Brief History
To really understand IR35 today, it helps to know how it has changed over time:
- 1999: The Inland Revenue announced plans to tackle disguised employment.
- 2000: IR35 became law through the Finance Act. Initially, contractors themselves had to determine if their contracts were inside or outside IR35.
- 2011: Partial changes were made, but the system remained complex.
- 2017: Public sector reform: responsibility shifted from contractors to public sector bodies, making organisations decide the IR35 status of contractors they hired.
- 2020 (delayed to 2021 due to COVID-19): Private sector reform: medium and large businesses became responsible for deciding contractor status.
- 2022: The government briefly announced plans to scrap the reforms, but within weeks, this decision was reversed.
- 2025: As of now, the legislation stands, and contractors continue to face strict compliance rules.
These reforms have reshaped the contracting industry. They have also increased uncertainty, especially for contractors worried about being wrongly placed inside IR35.
Who is Responsible for IR35?
Responsibility depends on the size and sector of the business engaging the contractor:
- Before 2017: Contractors themselves were responsible for assessing their own IR35 status.
- 2017 to present (public sector): Public bodies must decide if a contractor is inside or outside IR35.
- Since April 2021 (private sector): Medium and large businesses are responsible for status determinations.
- Small businesses: Exempt from the reforms. Contractors working with small businesses remain responsible for their own IR35 assessments.
This shift in responsibility means contractors no longer have full control. Businesses need to carry out proper status determinations, often using HMRC’s CEST tool, but many organisations still struggle to apply the rules correctly.
Inside IR35 vs Outside IR35
The terms inside IR35 and outside IR35 are central to the legislation. Here’s what they mean:
Inside IR35:
- You are treated like an employee for tax purposes.
- Your client or agency must deduct Income Tax and NICs at source through PAYE.
- You have less control over how you manage your income.
- You cannot claim the same range of business expenses as you would if you were outside IR35.
Outside IR35:
- You are classed as genuinely self-employed.
- You can pay yourself through dividends and salary in a more tax-efficient way.
- You have more control over your working arrangements.
- You can claim legitimate business expenses.
Key IR35 Status Indicators
Three major factors determine whether you fall inside or outside IR35:
- Control: Does your client control how, when, and where you work? More control suggests employment, pushing you inside IR35.
- Substitution: Do you have the right to send someone else to carry out the work? If not, this is a red flag for IR35.
- Mutuality of Obligation (MOO): Is there an ongoing obligation for the client to provide work and for you to accept it? If yes, you may be inside IR35.
Contracts should be carefully worded and reflect your actual working practices, as HMRC looks at both the written terms and the reality of how you work.
IR35 Advice for Contractors and Businesses
Because IR35 can be complex and costly if misapplied, seeking expert advice is essential. Here’s where professional support comes in:
IR35 Specialists: Experts who review contracts and working practices to assess IR35 status accurately. They help contractors and businesses avoid mistakes that can trigger HMRC investigations.
IR35 Accountants: Accountants who understand off-payroll working rules can guide you on compliance, structure your pay efficiently, and prepare records in case of an HMRC review.
IR35 Advice Services: Many advisory firms offer mock audits, legal contract reviews, and practical support on disputes with HMRC.
Using these professionals is not just about compliance. It is also about protecting your income, reducing tax risks, and ensuring peace of mind when taking on new contracts.
IR35 Red Flags: How to Know if You’re Inside IR35
One of the biggest challenges for contractors is recognising when a contract might fall inside IR35. Being unaware can lead to unexpected tax bills, penalties, and reduced income. Here are some of the most common red flags:
- No right of substitution: If you cannot send someone else to complete the work, HMRC may view this as employment.
- High level of client control: If the client decides when, where, and how you carry out tasks, you are more likely to be seen as inside IR35.
- Mutuality of obligation: If there is an expectation of ongoing work beyond the current project, this looks more like an employment relationship.
- Integration into the business: Using a client’s equipment, being part of staff meetings, or having a company email address can all signal employment rather than contracting.
- Lack of financial risk: Employees do not usually face financial risks, whereas genuine contractors should have business risks, such as the chance of making a loss.
If several of these apply to your contract, it may be a sign that you are inside IR35. This is why regular reviews of contracts and working practices are essential.
IR35 Exemptions and Special Cases
Which Companies Are Exempt from IR35?
Not every business is required to assess contractors under the IR35 reforms. According to the Companies Act 2006, small businesses are exempt. To qualify as a small business, the company must meet two or more of the following conditions:
- Turnover of no more than £10.2 million.
- Balance sheet total of no more than £5.1 million.
- No more than 50 employees.
If you are working for a small business, as the contractor, you remain responsible for determining your own IR35 status.
Does IR35 Apply to Non-UK Residents?
Yes, IR35 can apply to non-UK residents if they are working for UK-based clients through a limited company registered in the UK. The key factor is whether the work is carried out for a UK business and falls within HMRC’s jurisdiction.
However, if the contract is entirely with an overseas company and there is no UK connection, IR35 may not apply. Contractors in this situation should seek professional IR35 advice, as international tax rules can be complex.
IR35 Changes and Future Outlook
Any Changes in IR35?
Since its introduction, IR35 has seen several reforms. The biggest changes came in 2017 (public sector) and 2021 (private sector), where responsibility shifted from contractors to end clients.
In 2022, the government briefly announced that the reforms would be scrapped from April 2023, which would have returned responsibility to contractors. However, this decision was reversed just weeks later, meaning the reforms remain in place.
Will IR35 Be Scrapped in 2025?
As of now, there are no confirmed plans to scrap IR35 in 2025. Some industry groups continue to lobby for reform or repeal, arguing that the rules are unfair and damaging to the contracting sector. While the debate continues, contractors should plan on the basis that IR35 is here to stay for the foreseeable future.
How to Stay Compliant and Avoid IR35 Issues
Navigating IR35 does not need to be overwhelming. By taking proactive steps, you can reduce your risk and maintain control over your contracts:
1. Get contracts reviewed: Have a specialist check the wording of your contracts to ensure they reflect genuine self-employment.
2. Work with IR35 accountants: A good accountant will help you stay compliant while maximising your take-home pay.
3. Keep evidence of independence: Maintain records that show you control your work, can substitute others, and take on financial risks.
4. Avoid employee-like behaviour: Do not accept company perks such as holiday pay, sick pay, or staff benefits.
5. Use HMRC’s CEST tool cautiously: While it can give an indication, it is not always accurate and has been criticised for producing inconclusive results.
The goal is not just to avoid being wrongly classed inside IR35, but to build a clear, defendable case for your working practices should HMRC investigate.
The Bottom Line
IR35 continues to shape the way contractors and businesses operate in the UK. It was designed to prevent disguised employment, but in practice, it has caused uncertainty and added complexity.
For contractors, the key is to understand the difference between being inside and outside IR35, know the red flags, and take proactive steps to protect your status. For businesses, compliance is vital to avoid penalties and maintain good relationships with skilled contractors.
While debates about the future of IR35 continue, one thing is certain: the rules are not going away soon. With the right advice from specialists and accountants from Sigma Chartered, you can stay compliant, protect your earnings, and continue to enjoy the flexibility that contracting brings.
