This article discusses the fiduciary duties of an agent to the principal and the concept of corporate separate personality and limited liability of companies in the United Kingdom. It explains the duties of an agent to follow the lawful and reasonable instructions of the principal, the duty of care and skill, the duty to avoid conflict of interest, the duty not to act for his own benefit or the benefit of a third person without the informed consent of the principal, the duty not to accept a bribe from a third party that is secret from the principal, the duty to account, and the duty not to delegate authority. It also explains the concept of corporate separate personality and limited liability of companies in UK with reference to the case of Salomon v Salomon [1896].