How To Write A Letter Of Invitation Foriegn . Send a letter of invitation when you are inviting someone to be included in something, such as an event. Consulate and applying for the visa or already has a visa, but will still need to get past u.s. How to write Invitation Letter for Chief Guest from dailyprintablecalendar.com The invitation letter should only mention the reason or the purpose of the. As per our previous conversation, we are sending the planning and requirements and the target of our company (mention the name of the company). If a foreign company is inviting a visitor, an ambassador of the company should write the letter.