In
Market Investigations Ltd v The Minister of Social Security Mr. Justice Cooke said: "Is the person who has engaged himself to perform these services performing them as a person in business on his own account? If the answer to that question is 'yes' then the contract is a contract for services. If the answer is 'no' then the contract is a contract of service."
In
Hall v Lorimer Mr. Justice Mummery said: "In order to decide whether a person carries on business on his own account it is necessary to consider many different aspects of that person's work activity....The object of the exercise is to paint a picture from the accumulation of detail".
HM Revenue & Customs accept that the IBOYOA approach has received extensive judicial approval.
In practice, what this means is that although each engagement has to be viewed on its own merits, and there is nothing stopping a self-employed person from also being an employee, your credibility for IR35 purposes will be improved if your company has the appearance of being a genuine business. For example, if you have numerous clients, especially concurrent clients, your own workshop of office facilities and equipment, employees or subcontractors, are actively seeking or tendering for contracts, advertise on a regular basis, have your own business cards and stationery, etc., have non-contracting sources of income, and give the general appearance of being an entrepreneur, you are less likely to be perceived as a disguised employee, than the contractor who works for only one client over a number of years and makes no real attempt to generate other income. It is a case of creating an image, or as Mr. Justice Mummery said, painting a picture.