Indian Contract Act, 1872
187. Definitions of express and implied authority
An authority is said to be express when it is given by words spoken or written. An authority is said to be implied when it is to be inferred from the circumstances of the case; and things spoken or written, or the ordinary course of dealing, may be accounted circumstances of the case.
A owns a shop in Serampur, living himself in Calcutta, and visiting the shop occasionally. The shop is managed by B, and he is in the habit of ordering goods from C in the name of A for the purposes of the shop, and of paying for them out of A's funds with A's knowledge. B has an implied authority from A to order goods from C in the name of A for the purpose of the shop.