Getting your tax right in the UK is already tough, but when you’re dealing with contractors or thinking about off-payroll working, IR35 adds more questions.
IR35 is a set of off-payroll working rules in UK tax legislation that decide if a contractor should pay tax like an employee. In simple terms, these rules are about stopping tax avoidance, but they can affect your business in many ways.
If you want to stay compliant, especially if you run a crypto or small business, understanding the basics is a must.
What Is IR35?
IR35 legislation looks into people who work like an employee but claim to be self-employed to pay less income tax and national insurance. IR35 looks at work through an intermediary, usually a limited company, sometimes called a personal service company.
If you, as a business, hire a contractor through an intermediary, IR35 helps determine whether that worker is really an employee for tax purposes.
Not all contractors fall under IR35 off-payroll rules. The rules only apply if the contractor would be seen as your employee without the intermediary. There are lists of tests for this, which can feel confusing.
Origins of IR35
IR35 was the name of the press release from the then Inland Revenue which announced the Intermediaries Legislation introduced in 2000, and has become the common term to refer to the legislation. At the start, was aimed at contractors who set up limited companies to avoid paying income tax and national insurance. Many people took advantage, so the government made a law about it.
The law focused on “disguised employees.” These are people who act and work like your staff but send an invoice from their own company. Over time, as tax laws changed and loopholes closed, HMRC kept looking for ways to make IR35 stricter.
How Does IR35 Work?
When a business wants to hire a contractor, it needs to decide if IR35 applies. If IR35 does apply, then the person should be treated “inside IR35” and pay tax like an employee. This means income tax and national insurance contributions are taken at source, just like a normal worker. If the contractor is “outside IR35,” they pay tax like a self-employed person.
Who makes this call? For public sector and most private sector clients, the business must decide the IR35 status—not the contractor. There are specific rules for small businesses and special tools, like the CEST tool from HMRC, to help.
3 Key Tests for IR35 Status
There’s no single formula that says if someone is inside or outside IR35. HMRC uses several tests to help you decide. Each test looks at different things in the contract and actual work. Do you really manage the contractor? Can they send someone else to do the job? Do you have to give them constant work? If most of these tests show a close relationship, like employment, IR35 likely applies. If not, you’re probably outside IR35. But interpretation can be tricky, so records and clarity matter a lot.
1. Control
The control test checks if your business controls how, when, or where the contractor works. If you say where to sit, what hours to keep, and how to do the job, this looks like an employee. If the contractor can choose how they work, it might be self-employment.
Control isn’t just about being the boss. Even little things, like telling a contractor how they must do each task, can pull them inside IR35. The less control your business has, the better your chances are for a contractor to stay outside IR35.
2. Substitution
This test looks at whether the contractor can send someone else to do their work. If your business says only that one contractor can do the work, it points towards employment. But if the contract and reality allow sending in a substitute, this shows genuine self-employment.
The right to substitute has to exist in practice, not just on paper. If you’d never actually accept a substitute, the test fails. Have you checked your actual working practices here?
3. Mutuality of Obligation
This one asks if your business has to offer ongoing work, and if the contractor needs to accept it. If there’s always more work and the contractor must take it, this is a strong sign of employment. If the job is project-based and ends when the task is done, it leans towards self-employment.
Real life matters more than a written contract. If, for instance, both sides expect work to continue even after one piece is finished, IR35 rules might come into play.
Recent IR35 Reforms
Starting in April 2021, big reforms changed who decides if IR35 applies. Before this, contractors decided their own status. Now, for public sector and medium and large private sector clients, the responsibility falls on the end client. If you’re a small business, the contractor still decides.
This change aimed to close gaps. Many businesses weren’t applying the rules strictly, so HMRC lost a lot of money. Now, businesses face more checks and need to keep records showing how they decide IR35 status.
Why IR35 Matters to Your Business?
If your business hires contractors, IR35 can affect your costs and operations. If you get IR35 wrong and treat someone as a contractor when they’re really an employee, you may have to pay back taxes and national insurance contributions. This can lead to large fines from HMRC.
It also matters for planning and budgeting. Bringing someone “inside IR35” often costs more, since you pay extra in taxes. And if you work with crypto or tech, new rules make it riskier to ignore compliance.
Who’s Affected by IR35?
The rules target mainly medium and large companies, but others can get caught too. Contractors working through their own limited companies (personal service companies) are the main group. If you are a small business, the contractor checks their IR35 status. For everyone else, you must check each case.
Anyone who works for a business but uses an intermediary to get paid should check if the rules apply. The rules might not affect sole traders directly, but tax and national insurance rules still matter for them.
Risks of Inside IR35 Non-Compliance
Ignoring IR35 or failing to comply can hit hard. HMRC can investigate your business, ask for taxes back, and issue serious fines. You could also end up with a poor business reputation. Have you thought about how this could affect your contracts in the crypto world?
Non-compliance brings not just money loss but can threaten your future. It often leads to audits, more paperwork, and added stress for everyone involved.
Benefits of IR35 Compliance
Sticking to the rules helps you avoid penalties and fines. It builds trust with HMRC and your contractors. You can plan better, knowing your costs. For crypto tax purposes, compliance shows you take tax and employment status seriously.
Good records and clear steps also mean less chance of disputes. Maintaining compliance can also help you attract better contractors, as they know your business handles things right.
How to Get IR35 Compliance Right
The key is attention to detail and clear processes. Start by checking every contract and every contractor. Use the HMRC tools if you’re unsure. Keep paperwork for each decision.
It’s not enough to just set rules on paper. You need to follow through with actual working practices that match your written contracts. If you’re unsure, professional advice can help.
4 Steps to Determine IR35 Status
Working out IR35 status is a step-by-step process. Get all contracts in writing and check working practices. Use the CEST tool and keep your Status Determination Statement (SDS) for each case.
Even if you think you know, always check again if working conditions change or you renew contracts. This helps protect against mistakes.
1. Review Contract and Working Practices
Read every contract for clear terms. What does the agreement say about hours, tasks, payment, and control? Also, look at real-life working practices. If these are different from what’s written, HMRC will focus on reality.
2. Check Actual Working Practices
Just because a contract says one thing doesn’t mean you follow it each day. See if your working practices match what’s written. Are contractors really choosing how, when, and where they work? Or do you treat them like staff in reality?
3. Use HMRC’s CEST Tool
The CEST (Check Employment Status for Tax) tool from HMRC can help you work out IR35 status. You answer questions online about the contract and how work is done. It offers guidance on whether someone is inside or outside IR35.
4. Document Status Determination Statements
Always give a written Status Determination Statement (SDS) to each contractor and keep a copy. This statement explains your decision about their IR35 status and why you made it. Keep these records for HMRC if they ask in the future.
Common Challenges with IR35 Compliance
IR35 compliance is not easy. It’s confusing to decide who should be classed as inside or outside IR35. The rules can be hard to follow if you’re busy or the contracts are complex.
There’s also lots of paperwork. Keeping track of changes and new determinations for each contractor can feel like a full-time job.
Disputes Over Status Determination
Sometimes contractors disagree with your IR35 assessment. They might say they’re self-employed, but your review says otherwise. When this happens, set up a process for handling disputes. You need to respond within 45 days and give clear reasons for your decision.
Open communication helps. It shows you are serious about compliance and care about getting things right.
Administrative Burden
IR35 brings lots of admin. You must check every contract, keep records, and answer to HMRC if needed. This takes up time and can feel like extra work. Still, it’s better than facing a tax enquiry later.
Hiring help or using a tax adviser can lift some of this burden and give peace of mind.
Contractor Resistance
Contractors may push back against being put inside IR35. They know it means paying more tax and losing the ability to take income as dividends. Some might ask for more pay to make up for it, or even refuse jobs.
Keep the conversation honest. Explain your processes, show your paperwork, and try to meet halfway if possible.
Best Practices for Ongoing IR35 Compliance
Getting IR35 right once isn’t enough. You’ll need to review, update, and repeat the process for each new contract or contractor.
Regularly Review and Update Contracts
Don’t use old contracts for new work. Every agreement should be up-to-date and reflect actual working practices. If you change how contractors work, update the documents too.
Align Actual Working Practices with Agreements
Contracts are important, but what happens every day matters more. Make sure your business and contractors follow the agreement in reality. If working practices drift, fix them or update the contract.
Train Hiring Managers on Employment Status Tests
Anyone who hires or works with contractors should understand the main IR35 tests. Offer training so your team can spot risks early and handle things correctly.
FAQs
How can businesses ensure their working practices align with IR35 requirements?
Businesses can stay compliant by matching written contracts with what actually happens in the workplace. Clear agreements about control, substitution, and mutuality of obligation are a good start. Managers should check regularly that how the contractor works day-to-day fits the contract. If things change, update the agreement and review the IR35 status again. Open communication with contractors about expectations helps as well.
How often should a company perform an IR35 assessment for ongoing projects?
Each time there’s a new contract or a big change to working practices, it’s wise to review IR35 status. Regular reviews, at least once per project or every year, can stop surprises. Circumstances change, and what was outside IR35 last year may not be this year. Frequent assessments also help keep records in case HMRC asks for proof later.
How does IR35 apply differently to public sector versus private sector clients?
For the public sector, the responsibility for determining IR35 status has been with the hirer since 2017. For private sector clients, this shift happened in April 2021 for medium and large businesses. Small business clients in the private sector leave the responsibility with the contractor. The biggest difference is who makes the final call and who is responsible for paying income tax and national insurance if the rules apply.
What steps should a contractor take to check employment status for tax and comply with IR35 regulations?
Contractors should review all client contracts and look at actual working practices. Using the HMRC CEST tool helps. Keep records of decisions and talk with the client if you’re unsure. If working with a small business, you have to make the call yourself. If the client is bigger, ask for their Status Determination Statement. If you disagree with their IR35 status decision, raise it early and ask for a formal review.
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