Inside IR35 vs Outside IR35

What is IR35?

IR35 is the shorthand term for the Intermediaries Legislation (Chapter 8, ITEPA 2003) and the Off-payroll Working rules (Chapter 10, ITEPA 2003). It is designed to identify "deemed employees" who are workers providing services through an intermediary, such as a Personal Service Company (PSC), but work in a manner that resembles traditional employment.

What is the aim of IR35?

HMRC’s objective is to prevent workers from accessing the tax efficiencies of a corporate structure if their relationship with the client is, in substance, one of employment. If a contractor is deemed to be ‘Inside IR35’, Income Tax and National Insurance Contributions (NICs) must be paid equivalent to those of a permanent employee.

How has IR35 evolved?

Introduced in 2000, the responsibility for determining status originally sat with the contractor. This changed with the 2017 reforms in the public sector and the 2021 reforms in the private sector. For engagements with medium and large businesses, responsibility for determining status and liability for unpaid tax now rests with both the hiring organisation and the agency.

What does it mean to be Inside IR35?

Being Inside IR35 means that for tax purposes, the worker is treated as a "deemed employee." This does not typically grant the worker statutory employment rights (like holiday pay or pension), but it does require that their fees are processed via PAYE.

What are the implications of being Inside IR35?

For the contractor, the primary implication is a reduction in take-home pay due to the deduction of Income Tax and Employee NICs at source. For the hiring business or agency (the fee-payer), engaging contractors on an inside IR35 basis requires payment of Employer NICs and the Apprenticeship Levy on top of the contractor’s gross rate.

What does it mean to be Outside IR35?

An ‘Outside IR35’ determination means the engagement is a genuine business-to-business relationship. The contractor is operating as a self-employed consultant. They are responsible for their own taxes, and the fee-payer can pay the PSC’s invoices in full without tax deductions.

What are the implications of being Outside IR35?

Contractors generally prefer an outside IR35 status because it allows them to manage their own company finances and taxes. For businesses, outside IR35 engagements are more cost-effective and provide access to a wider pool of high-level specialist talent who refuse to work on an inside IR35 basis.

Who is responsible for determining IR35 status?

If the end client is a public authority or a medium-to-large private-sector business, the client is legally responsible for determining the status and can issue a Status Determination Statement (SDS). If the client is a "small" business for off-payroll purposes or has no UK permanent establishment, the responsibility remains with the contractor.

What are the key factors in an IR35 assessment?

To determine status, we must look at the primary "pillars" of case law:

• Control: This assesses whether the hiring business has the right to exercise sufficient control over how, what, when, and where the contractor performs the work. Independent contractors generally maintain high operational autonomy over their delivery.
• Substitution: This determines whether the contractor must perform the work personally or has a genuine, unfettered right (not controlled, limited, or prevented by anyone) to provide a qualified substitute to complete the services on their behalf.
• Mutuality of Obligation: This assesses whether the hiring business is obliged to pay the worker for the work performed and whether there is an ongoing obligation to offer and accept work. A lack of sufficient mutual obligations can be a strong pointer toward genuine self-employment.
• Other Factors: Any other relevant factors, such as financial risk, being in business, or level of integration, can be considered.

Why is an accurate IR35 determination important?

Accuracy is vital because HMRC can challenge a determination and seek repayment of tax, interest, and penalties. If a business fails to exercise reasonable care in making a decision, it can be held liable for the full tax shortfall across its entire contingent workforce.

What is Reasonable Care?

Reasonable Care is a case-law-defined standard a hiring organisation must meet when determining a worker’s IR35 status. HMRC do not provide a one-size-fits-all definition, but they expect a business to act as a "prudent and reasonable taxpayer" would, in their specific circumstances. If a business fails to demonstrate reasonable care, the financial liability for unpaid tax and National Insurance shifts directly to them, even if they aren't the entity paying the contractor.

What tools are available for IR35 assessment?

HMRC provides a tool called CEST (Check Employment Status for Tax). However, CEST is frequently criticised for being outdated, inaccurate and providing "unable to determine" outcomes in over 20% of cases. Professional solutions, like IR35 Shield, provide a more robust assessment defence by using questions that are actually aligned with IR35 case law. IR35 Shield’s status tool is backed up by IR35 experts and specialist IR35 services for contractors and businesses.

What are the penalties for getting IR35 wrong?

If a status assessment is found to be incorrect and the client is deemed to have failed the reasonable care test, penalties can reach up to 70% of the unpaid tax. For a single contractor on a high day rate, the total bill for tax, NICs, and penalties can easily reach tens of thousands of pounds per year of the engagement.

What are the best practices for managing IR35?

1. Assess every engagement: Re-assess whenever a contract is renewed or when working practices change.
2. Ensure the contract matches reality: Perform a working practices review to ensure the day-to-day delivery aligns with the written agreement.
3. Collaborate with the supply chain: Keep open communication between the client, agency, and contractor to ensure the SDS is understood and accepted.