In some cases, the principal might agree to make the grant of authority to the agent irrevocable. Despite this, an agent’s power is not actually made irrevocable simply by the principal agreeing that it should be so. If it is a term of the agency agreement that the agent’s authority is not to be revoked for a specified period or while particular circumstances exist, the agency power may still be revoked by the principal or renounced by the agent, though potentially giving rise to liability for breach of contract.
An agent’s power is only made truly irrevocable (so that any attempt to revoke it is legally ineffective) if the grant of authority to the agent was made for the purpose of securing some interest of the agent. This is the case when an agency power is given to provide security for the repayment of a debt owed by the principal to the agent. A debtor might give their creditor an agency power to enable the creditor to sell the debtor’s property if the debtor fails to repay the debt owed. Such a power, intended as a security for the benefit of the creditor, cannot be revoked before the debt is repaid.