All activities that facilitate smooth flow of goods from manufacturing centres to the consumption centres are called aids or auxiliaries to trade. 

Aids to trade may be classified into five categories:

(i) Transportation: Selling all the goods produced at or near the production centres is not possible. Hence, goods are to be sent to different places where they are demanded. The medium which moves men and materials from one place to another is called transport.

(ii) Warehousing: Storage is indispensable in these days of mass production. The goods should be stored carefully from the time they are produced till the time they are sold, hence, the need for warehousing. Warehouses are also called godowns.

(iii) Insurance: The goods may be destroyed while in production process or in transit due to accidents, or in storage due to fire or theft, etc. The businessmen would like to cover these risks. Insurance companies come to their rescue in this regard.

(iv) Advertising: Advertising is an effective aid in selling the goods. The producer, through advertisement, communicates all information about his goods, to the prospective consumers and create in them a strong desire to buy the product. Advertising can be carried in different ways. It can be indoor or outdoor. Communicating with people through advertising, when they are in their homes, is called indoor advertising. 

(v) Banking: Now-a days we cannot think of business without banks. To start the business or to run it smoothly we require money. Banks supply money. A bank is an organization which accepts deposits of money from the public. withdrawable on demand or otherwise, and lends the same to those who need it.