A typewritten and notarized business letter ( the business letter should be notarized at the City Council or at the Prefecture/Mairie) on company letterhead stating the nature of business to be performed, the name and address of a reference to be contacted in the Republic of Congo. The invitation letter must be addressed to the Embassy of the Republic of Congo, Visa section. No business visa will be granted without an official business letter and please be aware that the business invitation letter should be only for 3 months from the date of its issuance.