Write an inquiry letter to ask for more information concerning a product, service or other information about a product or service. These letters are often written in response to an advertisement that we have seen in the paper, a magazine, a commercial on television when we are interested in purchasing a product, but would like more information before making a decision. Inquiries are also written to ask for business contact information to develop new business. For further types of business letters use this guide to different types of business letters to refine your skills for specific business purposes such as terms and discounts, terms of delivery, transportation method, cash items, insurance, making inquiries, adjusting claims, writing cover letters and more. Content writing should be concise, easy to understand and read.