Search

How can we help?

Icon

IR35 – Government’s CEST tool produces undetermined outcome

The Government’s CEST tool, designed to help determine whether a worker will be caught by the changes to the off payroll working rules (IR35) was unable to reach a conclusion in 19% of cases checked in the last year.

In data released by HMRC, between 25 November 2019 and 24 November 2020 the CEST tool delivered 975,416 outcomes. Of these outcomes:

  • 505,598 (52%) found the worker fell outside the IR35 rules;
  • 281,099 (29%) found the worker would be inside IR35; and
  • 188,719 (19%) were undetermined.

HMRC note in its comments alongside the data that in ’more finely balanced cases’, the tool will produce an ‘undetermined’ outcome and advises users to refer to their detailed IR35 guidance to make their decision on whether a worker falls within IR35.

281,099 (29%) found the worker would be inside IR35

Responsibility for making these status determinations is due to shift from the worker to the ‘end user’ client on 6 April 2021, but specialists such as Qdos have voiced concerns that the tool still is not ‘up to scratch’ following its update in November 2019 and will leave users without the clarity they need to make these decisions.

There are currently no plans to update the CEST tool further, as HMRC believe adding in the more complex questions needed to reach an outcome in more cases would make ‘increase the burden’ for most people using the tool. They will however publish this data on a quarterly basis going forward, in a bid to improve user confidence in the tool.

Should you have any queries about IR35, including about status determinations, our employment team is on hand to help.

Disclaimer
This information is for guidance purposes only and should not be regarded as a substitute for taking legal advice. Please refer to the full General Notices on our website.

Author profile

About this article

Read, listen and watch our latest insights

art
  • 02 July 2026
  • Litigation and dispute resolution

Litigation and Artificial Intelligence: Where are we now?

In the recent case of Cork and another v Smith, the High Court publicly admonished a law firm and two of its solicitors after they had produced and submitted two AI-generated letters to the court containing misleading and false information in relation to a block transfer application made under Rule 12.37 of the Insolvency (England and Wales) Rules 2016.

Pub
  • 30 June 2026
  • Litigation and dispute resolution

Overview of the new ICC Arbitration Rules: Key changes – Episode 1

In this episode, Jack Hobbs (Clarkslegal) and Christopher Howitt (Three Stone) discuss the major updates in the ICC Arbitration Rules 2026 and what they mean for practitioners, clients, and the future of international arbitration.

art
  • 26 June 2026
  • Corporate and M&A

Exit Readiness Consultation: Prepare your business for a successful sale

Take the first step toward a smoother, more profitable business exit. Our Exit Readiness service provides tailored health checks, expert guidance, and a free initial consultation—helping you address potential issues early and maximise your sale value.

art
  • 25 June 2026
  • Immigration

Justice and Home Affairs Committee – Settlement, Citizenship and Integration: What the House of Lords Report Means for Migrants

Discover how the House of Lords report influences UK settlement, citizenship, and integration policies. Learn what it means for migrants and employers.

art
  • 24 June 2026
  • Employment

What are employer’s obligations during a heatwave?

During the summer, employers can come across employee issues relating to the heat and hot weather. How can employers handle hot weather and what are employer obligations during a heatwave?

art
  • 23 June 2026
  • Employment

Pride month and employment law: Ensuring compliance with LGBTQ+ protections

With each Pride month, companies unveil rainbow logos and send office wide emails of solidarity. These gestures are valuable, giving visible demonstrations of support, but only really make a difference if those companies are able to truly say that their policies and practices are inclusive and legally compliant.