There are two parts to writing a business letter of introduction, Introducing a person or company and Introducing a product, equipment or service.The following explains how to write both types of business letter of introduction.

Introducing a person or company
Introduce the person or company and give the reason(s) for the introduction. If possible, express the reasons in terms of the reader's interest.

In the business letter of introduction, give background information from your personal experience about the person, service, product, or company.

Indicate any referral action you've taken, but avoid obligating the reader. Make it easy for the reader to make contact.

Express appreciation for any courtesy shown to the person being introduced.

Introducing a product, equipment or service
Introduce the product, equipment or service immediately.

Explain how the new product, service, or equipment differs from whatever is already available: Is it less expensive? Easier to use? More accurate? Safer? State exactly what its significance is.

Mention any exceptions to primary use or application. Who is ineligible to use this service, product, form, equipment? What are its limitations?

Make the item or service easy to investigate. Most readers approach anything new with a wait-and-see-what-everybody-else-thinks hesitancy. Consider offering a sample; an attached illustration; a “case study” explanation; a demonstration; a class; or readily available assistance by phone, visit, or display.

In memos, use the term “new” or its equivalent in the subject line to call immediate attention.