The great majority of workers whose employment status is likely to be challenged do provide their customers or clients with a personal service, at least for some of the time. This includes, of course, those workers who operate through their own Personal Service Companies, at which the IR35 provisions were intentionally targeted.
An employee will always be obliged to provide a personal service. However, many genuinely self-employed people will also have to provide a personal service, because their skills are unique and without them their business could not function. Nevertheless, HM Revenue & Customs regard the provision of a personal service as a strong indicator of employment.
Personal Service Companies that wish to remain outside IR35 will generally need to ensure that their arrangements with their clients are such that there is no obligation to provide the personal service of any particular worker. In achieving this, the starting point will be a formal agreement with the client that makes it clear that the Personal Service Company is providing specific services, rather than a person. The services to be provided should be described in precise terms, and there should be no suggestion that all of the work is to be done by one individual, names or otherwise.
See also
IR35 Compliance Guide - Right of Substitution