Capita is a British professional services company that provides business process management and consulting services. It is listed on the London Stock Exchange and is a constituent of the FTSE 100 Index. The term 'capita' is derived from the Latin word for 'HEAD' and is used to refer to the population of a country or region. In the crossword, the three-letter solution PER refers to the company's core business of providing Professional, Environmental and Regulatory services.