FEACO is the European federation of management consulting associations.

A consultancy shall at all times maintain the highest ethical standard in the professional work undertaken, and in matters relating to a client's affairs act solely in the interests of the client. Below you find a summary of the guidelines. The complete and actualised Guidelines of Professional Conduct you may find on FEACO's website. 
 
It shall be regarded as unprofessional conduct for a consultancy:

Rule 1 To disclose or permit to be disclosed confidential information concerning the client's business and staff.

Rule 2 To accept work for which the consultancy is not qualified

Rule 3 To enter into any arrangement which would detract from the objectivity and impartiality of the advice given to the client.

Rule 4 Not to agree with the client in advance on the terms of remuneration and the basis of calculation thereof.
  
Rule 5 To do anything likely to lower the status of Management Consultancy as a profession.

FEACO requires each member of a National Association to confirm to its National Association that its staff adhere to the Guidelines of Professional Conduct. Any member who in the opinion of its National Association's ruling body fails to comply with the Guidelines of Professional Conduct is liable to suspension from membership of that Association, and the privileges accorded to it by FEACO.

It is the duty of the National Association and the right of any member of that Association or aggrieved person to lay before the National Association's ruling body any facts indicating that a member has failed to observe the Rules laid down in the Guidelines of Professional Conduct.