A principal does not pay social premiums, holiday pay, pension premiums and suchlike. An independent professional pays taxes and premiums his/herself at the end of the year and will have to make reserves for this him/herself using a suitable rate. As a result of changes in the economy and market, because assignments last for a longer or shorter period of time or because competition in the professional area increases or decreases, no one suitable rate exists. The ultimate rate will always be as a result of negotiations between the assignee and the principal.
In addition to benchmarking, whereby your level of education, work experience and performances are compared to others in the same professional area, below you will find two methods which could serve as a basis for negotiations about an hourly rate and determining this rate.