Section 203 in The Indian Contract Act, 1872
Title: When principal may revoke agent's authority.
The principal may, save as is otherwise provided by the last preceding section, revoke the authority given to his agent at any time before the authority has been exercised so as to bind the principal.
Title: Revocation where authority has been partly exercised.
The principal cannot revoke the authority given to his agent after the authority has been partly exercised, so far as regards such acts and obligations as arise from acts already done in the agency.
(a) A authorizes B to buy 1,000 bales of cotton on account of A, and to pay for it out of A's moneys remaining in B‟s hands. B buys 1,000 bales of cotton in his own name, so as to make himself personally liable for the price. A cannot revoke B's authority so far as regards payment for the cotton.
(b) A authorizes B to buy 1,000 bales of cotton on account of A, and to pay for it out of A's moneys remaining in B's hands. B buys 1,000 bales of cotton in A's name, and so as not to render himself personally liable for the price. A can revoke B's authority to pay for the cotton.
Title: Compensation for revocation by principal, or renunciation by agent.
Where there is an express or implied contract that the agency should be continued for any period of time, the principal must make compensation to the agent, or the agent to the principal, as the case may be, for any previous revocation or renunciation of the agency without sufficient cause.
Title: Notice of revocation or renunciation.
Reasonable notice must be given of such revocation or renunciation, otherwise the damage thereby resulting to the principal or the agent, as the case may be, must be made good to the one by the other.
Title: Revocation and renunciation may be expressed or implied.
Revocation and renunciation may be expressed or may be implied in the conduct of the principal or agent respectively.
A empowers B to let A's house. Afterwards A lets it himself. This is an implied revocation of B's authority.