(a) Unsolicited enquiry
An unsolicited enquiry letter is written by a potential buyer interested in the best bargain. He does it at his own initiative and convenience. He writes to firms that sell the kind of product he requires or provides the kind of service he needs, trying to elicit information on price / costs, quality, availability and other terms of sale. An unsolicited enquiry, since it is at the writerâ€™s initiative has to be written in such a way that it gets the required response.The letter should have the quality of completeness and clarity. The writer should be able to give a complete idea of his requirement and the reasons for his enquiry in clear terms. If the enquiry is long, the writer can prefer to adopt a questionnaire format in the letter.
(b) A solicited enquiry
A solicited enquiry is in response to an advertisement / sales letter of a seller. Already the buyer has some information on the product or service. He requires further details. It is not as lengthy as an unsolicited enquiry. The questions relate to particular areas of a sale / service. A solicited enquiry may ask for a brochure / bulletin / catalogue or for a clarification of the items mentioned in them.
(c) Enquiries asking for a favour
Certain letters of enquiry seek the favour of an information with or without a commercial proposition. It may be merely seeking some information to be used later. A business organisation may be seeking information from another firm regarding credit worthiness of a businessman. A research scholar particularly engaged in market research may send a letter of enquiry with a questionnaire to a firm. Such enquiry letters should clearly spell out their objectives.