Generally letters of inquiry are written under following circumstances:
(i) When a person wants to buy goods for his self consumption (ii) When business firms wants to buy goods for selling (iii) When there is a speculation that there is giving to be shortage of goods. (iv) When there has been a substantial increase-decrease in price of goods (v) When the customer wants to inquire about any financial sales promotion scheme being introduced by the firm. (vi) When the raw material of the product is in shortage, the customer might inquire about the effect on the supply of the product. (vii) To inquire about price, bulk, quality, weight, packing, transport etc.