IR35 The off-payroll IR35 regime applies where: • from 6 April 2017, a public authority, and • from 6 April 2020, a private sector entity (other than one that is ‘small’) engages a worker via an intermediary such as a personal service company (PSC). The relevant legislation has effect in relation to payments made on or after the dates mentioned above even if such payments relate to services provided prior to those dates. Broadly, the effect of the off-payroll IR35 regime is, in relevant situations, to shift the responsibility for assessing whether IR35 applies from the PSC to the end client and, in the event IR35 does apply, to shift the obligation to make deductions in respect of income tax and National Insurance contributions (NICs) onto the party that is closest in the relevant contractual chain to the PSC (whether that party is the