Business Letter must be written on company letterhead— the letterhead must state the business address in the USA. Letter must also include the following:
Addressed to the corresponding Consulate/Embassy.
Name the applicant (traveler) sponsored or employed by the company.
Explain the nature of business to be conducted.
State the dates of visit.
State the name and address of the company to be visited.
Specify the type and validity of the requested visa.
Company guarantee of financial responsibility for all travel expenses.
An original closing signature (someone other than the applicant).