Formal invitation letters are commonly used by businesses to request the presence of clients or prospective clients at a special company event. They can also be used to invite guests to deliver speeches at company conventions and formal meetings. They are distinguished from personal invitation letters by their formality and the fact that an organisation or corporate unit is inviting the individual to the event, rather than one person inviting someone else to an event.
Open a word processing document on your computer, and create two or three carriage returns at the top of the page. Select a left alignment, single-spaced format for your text. Choose a font that is legible, such as Times New Roman, size 12, or Arial, size 10.
Type today's date as Month Day, Year. Enter two carriage returns, creating two blank lines of space, and type the address block for the person you are sending the letter to, using this format:
City, State ZIP
Enter three carriage returns after the address block, and type the greeting. For example:
Dear <Mr., Mrs. or Ms.> <Last Name>:
Enter another carriage return, and begin typing the letter.
State the reason you are writing in the opening sentence. For example, write, "On behalf of the board of directors for ABC Company, I would like to formally invite you to be the keynote speaker at our 2011 National Conference in Jacksonville, Fla."
Provide details about the conference in the next paragraph, including conference theme, location and dates. Mention other confirmed speakers if there are any. Create another paragraph with your expectations of how many guests will attend.
Type a closing sentence restating your request and thanking the person for his consideration. Enter a carriage return, and type a single sentence indicating when you will follow up your letter with a phone call to discern the person's response.
Enter a carriage return again and type your salutation, such as "Sincerely," "Cordially" or "Respectfully," followed by a comma. Enter three carriage returns and type your signature block:
Sign your name in the empty space between your salutation and signature block to give the letter a handwritten, personal touch. Place the letter in a typed envelope, and include a first-class postage stamp on the envelope.