The present document reviews the human factors issues of those centres where business is conducted via the telephone whilst simultaneously using Display Screen Equipment (DSE) and gives guidance on the design of the tasks and of the working environment. It classifies such call centres to facilitate the identification of specific tasks@ functions and supporting equipment. It reports a number of studies into the call centre working environment and consultations with stakeholders. Guidance is given in the context of current legislation and developing technologies. Human factors problems associated with call centre work are highlighted@ and where appropriate@ examples of best practice are given to illustrate how they may be avoided. The present document is applicable to call centres of various types such as help lines and telemarketing. It does not deal with issues related either to surveillance centres or to sex lines. It does not deal with web based contact centres. Recommendations in the present document are limited to real time voice based services although the implications of changing technology are noted. Although personal health considerations are included in the present document@ safety issues are outside its scope.