CEST and HMRC's employment status tools

CEST, the check employment status for tax tool, is the online questionnaire HMRC provides to help clients, agencies and contractors decide whether an engagement is inside or outside the off-payroll rules. HMRC says it will stand by the result where the answers given were accurate and the facts did not change. Since 2017 it has been the most used and most argued-over instrument in the IR35 system.

What came before

HMRC has tried to automate status since the early 2000s. The Employment Status Indicator was an online tool of the mid-2000s whose results HMRC would not be bound by. The business entity tests of May 2012, scored on twelve questions from business premises to advertising, were meant to sort contractors into low, medium and high risk bands and were abandoned in 2015 after the IR35 Forum concluded they mostly told contractors they were at risk. Each generation of tool has faced the same objection from the courts' side of the argument: employment status turns on the whole picture of a relationship, and a questionnaire cannot weigh it.

CEST since 2017

The employment status service was released in March 2017 for the public sector reform and renamed CEST. Its early versions returned no answer in a large minority of cases and, advisers found, gave inside results for engagements they regarded as clearly outside. Its treatment of mutuality of obligation, which it did not test at all on the basis that any contract implies it, was contradicted by the Court of Appeal and then the Supreme Court in the PGMOL referees case, and HMRC revised the tool in 2019 and again in 2025. Public bodies and large clients have often used it as a shield, treating its output as the determination rather than as evidence for one.

Use in 2026

Use of the tool fell sharply in 2026 as engagers turned to insured status reviews and to their own assessment processes, a shift the archive reported in June. The Freelancer and Contractor Services Association's guidance on enforcement evidence, published in July 2026, lists the status determination statement, the reasoning behind it and the contract-versus-practice record as what HMRC actually asks for. A CEST result on its own is not that record.

Using it well

Answer the questions from the working practices, not from the contract. Keep the printout with the determination and the reasons. Where the result is inside, use the dispute process the rules require the client to run. Where it is outside, make sure the facts on the ground match the answers given, because that is the condition on which HMRC's promise to stand by the result depends. The articles below track every version of the tool and its predecessors.