IR35-hub for Contractors: Rules, Resources & Expert Advice | ContractorUK

IR35-hub for Contractors

IR35 affects all contractors who do not meet HMRC's definition of self-employment. The legislation was designed to stop contractors working as 'disguised employees', by taxing them at a rate similar to employment. Understand the rules, determine your status, and protect your business.

43 Expert Guides
20-30% Pay impact if inside

Essential IR35 Resources

Quick access to the most important IR35 tools and services

Latest IR35 News

Breaking news and updates on IR35 legislation and enforcement

7th October 2025

Andrew Griffith MP says Tories would reform IR35

Shadow business secretary vows to 'look at reforming IR35' if the Conservatives are returned to power.

March 2025

Spring Statement 2025: Ten devils in the detail contractors must face

Chancellor's Spring Statement contains several issues contractors need to be aware of for the coming tax year.

April 2024

HMRC responds to Public Accounts Committee report

HMRC addresses PAC's report but doesn't fully engage with the charge that IR35 reforms deter economic activity.

August 2024

HS2 pays HMRC a 'staggering' £6.2million for mismanaging IR35

Public rail body run by ex-Revenue boss hits the buffers for not managing contractor IR35 status correctly.

April 2024

Lords defend contractors, issuing 'damning' IR35 verdict against Treasury, HMRC

House of Lords issues critical report on IR35 reforms, highlighting concerns about treatment of contractors.

2024

Like the defeat of the IR35 amendment, HMRC's attitude to contractors is disappointing

Criticism directed at HMRC's approach to contractors following defeat of an IR35 amendment.

2024

HMRC isn't listening on private sector IR35 reform

Evidence shows HMRC's lack of responsiveness to concerns about private sector IR35 reforms.

April 2024

New tax year 2024-25 begins for contractors

Key changes and considerations for contractors as the new tax year commences.

2024

Latest IR35 news and updates

Stay informed with the latest IR35 news, case updates, and legislative changes.

2024

All contractor news

Complete archive of contractor news including IR35, tax, and industry updates.

May 2025

IT contractor demand lost its footing in April 2025

Analysis of the contractor market showing declining demand in spring 2025.

June 2025

IT contractor demand in May 2025 ratchets up, verging on growth

Market data suggests potential turnaround for contractors following months of uncertainty.

April 2025

IT contractor jobs market in March 2025 moved closer to growth

Positive indicators emerge for the contractor market as spring approaches.

April 2025

Contracting Awards 2025 unveils 'stellar' shortlist of finalists

Recognition of excellence in the contracting industry with prestigious awards shortlist.

2024

What is IR35? Rules explained for contractors

Comprehensive explanation of IR35 legislation and its implications for UK contractors.

2024

IR35 case law and tribunal decisions

Analysis of important IR35 court cases and their impact on contractor status determinations.

2024

CEST tool guidance for contractors

Understanding HMRC's Check Employment Status for Tax tool and how to use it correctly.

2024

Off-payroll working rules: Complete guide

Detailed overview of off-payroll working regulations introduced in 2017 and 2021.

2023

Private sector IR35 reforms explained

Comprehensive overview of the private sector IR35 reforms and their impact on contractors.

2023

Public sector IR35 compliance guide

Understanding how IR35 operates in the public sector and compliance requirements.

2023

Substitution rights under IR35

How the right of substitution affects IR35 status determinations.

2023

Control factor in IR35 assessments

Understanding how control over work affects employment status for tax purposes.

2023

Mutuality of obligation explained

How MoO plays a critical role in determining employment status under IR35.

2023

Status Determination Statements guide

Understanding your rights regarding SDS documents under off-payroll working rules.

2023

Challenging IR35 status determinations

Steps contractors can take when disagreeing with an inside IR35 determination.

2023

IR35 blanket bans and contractor market impact

How risk-averse approaches to IR35 have affected contractor opportunities.

2024

Inside vs Outside IR35: Key differences

Clear explanation of what it means to be inside or outside IR35 for contractors.

2024

Responding to an IR35 investigation

Essential steps to take if HMRC launches an IR35 compliance check.

2024

IR35-compliant contract guidance

Key contract terms that support an outside IR35 status determination.

2024

Working practices vs written contracts

How tribunals weigh actual working practices against written contract terms.

2023

Personal Service Companies and IR35

Understanding PSC regulations and their relationship to IR35 legislation.

2023

Umbrella companies vs IR35 compliance

How umbrella employment compares to operating under IR35 rules.

2024

What does Outside IR35 mean?

Understanding outside IR35 status and the benefits for contractors.

2024

IR35 tribunal appeals process

Legal process for challenging HMRC IR35 assessments through the tribunal system.

2023

Historical IR35 developments

Archive of contractor news and IR35 legislative changes from 2023.

IR35 Guides by Category

Comprehensive guides covering every aspect of IR35

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Showing 10 guides
Essentials

What is IR35? IR35 rules explained

Essentially, the IR35 rules will affect all contractors who do not meet HMRC's definition of 'self employment'.

Essentials

What does Inside IR35 mean?

A refresher on what being caught by the Intermediaries legislation (or the off-payroll rules), really means.

Essentials

What does Outside IR35 mean?

Explainer for contractors on not being caught by the Intermediaries legislation.

Essentials

What is the cost of IR35?

How much being inside the off-payroll rules can set contractors back.

Essentials

What is a disguised employee?

An explainer of the IR35-related term every contractor wants to avoid becoming.

Status Determination

Mutuality of Obligations: How outside IR35 contractors can keep MOO at bay

Practical and contractual tips to stop Mutuality creeping in.

Status Determination

IR35: How PSCs can stop Control taking root on client projects

Equipment, attendance and workload. Just three off-payroll 'flashpoints' contractors need to get the right side of.

Status Determination

IR35: A contractor's overview to personal service

Successfully denying 'personal service' to HMRC is about much more than just having a substitution clause.

Status Determination

The right of substitution, not the IR35 silver bullet contractors might think

How to check your personal service bar is fine-tuned enough to be effective.

Investigations

What triggers an IR35 investigation?

Experts tell CUK how the taxman decides who to investigate under IR35.

Investigations

How to handle an IR35 investigation

What contractors can expect from an IR35 investigation: now and in the future.

Investigations

What NOT to accept from HMRC in an IR35 investigation

Leaving you in limbo isn't the only thing contractors should resist from a probing taxman.

Compliance

IR35 Contract Templates

Example contracts designed by IR35 experts with your compliance in mind.

Compliance

Off-payroll legislation: how it will affect limited company contractors

What we now know about the government's desired changes to IR35.

Compliance

Eight ways to help stop outside IR35 turning into inside IR35

'Get under the hood of client OPW advice' – and other top tips to keep status wrangles at bay.

CEST Tool

HMRC's IR35 CEST Tool: a contractor's overview

The who, what, when & how of the Check Employment Status for Tax tool.

CEST Tool

Getting the best out of CEST: How to work HMRC's IR35 tool if you must

Practical tips for getting accurate results from the Check Employment Status for Tax tool.

Essentials

How does IR35 status affect pay? Compare inside and outside IR35 rates

The pay when caught and not caught by the off-payroll rules is heading for a 26% gap.

Essentials

IR35 timeline: how it has changed since it came into force in 2000

The Intermediaries legislation's already bumpy journey through the years.

Essentials

How will I know if I am caught by IR35 and what will it cost me?

Introduction to factors determining your employment status and what IR35 will cost you.

Essentials

When clients reverse your contractor IR35 status overnight

A survival guide to shock horror – your 'outside' IR35 status getting ripped up and replaced with 'inside' IR35.

Essentials

How will IR35 change from April 2023?

What we know so far about the 2017 and 2021 IR35 reforms being repealed.

Essentials

How does IR35 insurance for contractors work, in practice?

Overview of what cover from the Intermediaries legislation/off-payroll rules actually looks like.

Essentials

Does taking an inside IR35 contract affect future mortgage applications?

How IR35 status impacts contractor mortgages and what lenders really look for.

Status Determination

How PSCs can stop Control taking root on client projects

Equipment, attendance and workload. Just three off-payroll 'flashpoints' contractors need to get the right side of.

Status Determination

Mutuality of Obligations: How outside IR35 contractors can keep MOO at bay

Practical and contractual tips to stop Mutuality creeping in.

Status Determination

IR35 is why it pays to have no notice period

MBF's IR35 win confirms there's sense in being truly dispensable as a contractor.

Status Determination

Unlike Neil McCann, contractors, keep your eye on the IR35 ball

Don't get caught offside with generic contracts; key factors against you, and witnesses that fail to score.

Status Determination

IR35: With secondary factors as his props, Stuart Barnes got over the line

The irreducible minimum's third aspect, plus secondary factors, got the Sky Sports commentator the one outcome he wanted.

Investigations

What happens in an HMRC IR35 investigation?

The actions, activities, and additional goings-on during an IR35 enquiry by HMRC.

Investigations

How to beat an IR35 enquiry

Seven areas contractors must be across to nullify HMRC scrutiny of their IR35 status.

Investigations

5 ways contractors can minimise the risk of an IR35 investigation

A silver bullet to stop HMRC is the stuff of legends. All the more reason to protect yourself with these five.

Investigations

A contractor's guide to IR35 penalties and interest

A need-to-know on HMRC penalising and charging interest under the Intermediaries legislation.

Investigations

HMRC status enquiry timeframes: don't miss IR35 deadlines

A rundown of the key timelines if probed by HMRC under IR35.

Investigations

What is the difference between tax enquiry insurance and IR35 insurance?

Contractors must know their cover, especially when up against an aggressive HMRC.

Investigations

What HMRC's IR35 offset-offer means for off-payroll contractors, and clients

A helpful 'pause' for the IR35-probed has now been confirmed.

Investigations

Top four IR35 red flags that could trigger an HMRC investigation

Contractors can do quite a lot to keep these four from being hoisted in HMRC's direction.

Compliance

Why Dragonfly got caught by IR35

And how other IT contractors might avoid the same traps.

Case Studies

What should contractors take from the Talksport IR35 case?

Six characteristics kept Kickabout Productions Ltd's contract for services onside.

Case Studies

Lorraine Kelly IR35 case: What contractors can learn

How the TV presenter won her IR35 tribunal and what it means for contractors.

Case Studies

Gary Lineker IR35 case: What happened and what it means

Analysis of the high-profile case and settlement with HMRC.

Case Studies

Kaye Adams IR35 case: TV presenter loses IR35 appeal

What contractors need to know about this landmark IR35 case.

Reforms & News

General Election 2024: Would abolishing IR35 constitute a tax cut?

Would a party that promises then delivers on repealing the IR35 off-payroll working rules be reducing the UK's tax burden?

Reforms & News

Andrew Griffith MP says Tories would reform IR35

Shadow business secretary vows to 'look at reforming IR35' if the Conservatives are returned to power.

Reforms & News

IR35 reforms: The 2023 reversal that never happened

What happened to the planned repeal of 2017 and 2021 IR35 reforms?

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Frequently Asked Questions

Quick answers to the most common IR35 questions

What is IR35?
IR35, also known as the Intermediaries Legislation, was introduced in April 2000. This complex piece of tax legislation was first proposed in the previous year's Budget, via a press release numbered IR35 with its purpose being to 'counter avoidance in the area of personal service provision'. The legislation affects contractors and freelancers working for a hirer and looks to see if the relationship for the contract duration (or 'relevant engagement') is actually one of employment.
How does IR35 status affect pay?
The pay when caught and not caught by the off-payroll rules is heading for a 26% gap. This significant difference is because contractors inside IR35 pay tax and NICs on a basis similar to employees, losing the tax advantages that come with genuine self-employment and limited company contracting.
What triggers an IR35 investigation?
A change in status. A high dividend low salary-split. Both are red rags to a potentially bullish HMRC. Experts tell CUK how the taxman decides who to investigate under IR35, with random selection by HMRC's compliance systems also playing a role in determining which contractors face scrutiny.
Will the Conservatives reform IR35?
Shadow business secretary Andrew Griffith MP has vowed to 'look at reforming IR35' if the Conservatives are returned to power. This follows ongoing concerns about the off-payroll working rules and their impact on the contracting sector since the 2021 reforms.
What are the recent changes to HMRC's CEST tool?
A new 'gateway question' on Mutuality is the most noticeable of numerous, non-material changes to the official IR35 tool. HMRC has made 'minor' yet 'helpful' changes to CEST, though the fundamental operation of the Check Employment Status for Tax tool remains largely unchanged.
What is HMRC doing about IR35 enforcement?
Contractors caught in IR35 checks face an HMRC energised by Mutuality, Control and Substitution. The taxman's MoO and Control wins, as substitution seemingly fails, make underway OPW audits 'risky' for many contractors currently under investigation.

Need Help with Your IR35 Status?

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IR35 Legislation – Further Reading

IR35, also known as the Intermediaries Legislation, was introduced in April 2000. This complex piece of tax legislation was first proposed in the previous year's Budget, via a press release numbered IR35 with its purpose being to 'counter avoidance in the area of personal service provision'.

The legislation affects contractors and freelancers working for a hirer and looks to see if the relationship for the contract duration (or 'relevant engagement') is actually one of employment.

More specifically, the aim of IR35 is to prevent those working through an intermediary, such as a 'personal service company', or one person limited company, from avoiding the higher levels of tax and NICs that they would be paying if, were it not for the intermediary, the relationship with the end client would be one of employment.

HMRC were particularly concerned that a worker could "leave work as an employee on a Friday only to return the following Monday to do exactly the same job as an indirectly engaged 'consultant' paying substantially reduced tax and national insurance." IR35 therefore was put in place to ensure that where an engagement is one of 'disguised employment', that the individual pays what HMRC cite as "broadly tax and NICs on a basis which is fair in relation to what an employee of the client would pay."