Use of HMRC's taxing IR35 status tool drops 71% in two years

Use of HMRC's own tool for checking compliance with the UK's controversial IR35 freelancer tax rules has fallen sharply, according to Freedom of Information data obtained by tax adviser IR35 Shield. The Check Employment Status for Tax tool, better known as CEST, was created to help firms decide whether contractors should be taxed like employees. But usage fell 43 percent during the 2025-26 tax year, and dropped 71 percent between 2023-24 and 2024-25, from 458,894 determinations to 135,178.