Consultants for professional services will be required to be in contract with their employers, In former years, consultants’ fees were determined by a scale set by the consultants’ professional institution and deviations from such scales were rare and discouraged. However, it is now more often the case that some negotiation and discussion takes place over the fee that wlii be paid for a specified service, and competition among consultants for particular projects is also to be found. This has resulted in a rethinking of the conditions under which consultants are engaged and both the clients and the consultants themselves are likely to have their own conditions. Where these conditions do not exist, model conditions are available, such as the ACE Conditions of Engagement published by the Association of Consulting Engineers (ACE) for consulting engineers and the Architect’s Appointment published by the Royal Institute of British Architects (RIBA).