Many rules of etiquette have fallen off over the years, but in business, writing a properly formed and worded letter is still an important factor in any business communication. The information for a proper letter heading should appear in a specific order from the top in either block format or indented format.
Dating a Business Letter
The first line of a letter should be the date when the letter is being sent. Format so the date is 2 inches from the top of the paper. If this is a standard United States business letter the month should be written out and the day and year should be in this format: June 30, 2009. Military and some other countries use a different date format, such as: 30 June 2009.
The Sender's Address
The sender's address is not necessary if the letter is going to be on company letterhead with the address printed on it, but if the letter is to be typed on plain paper, inserting the address of the sender one line down from the date is recommended by Purdue University, or it can be placed on the bottom of the letter after the signature. Other accepted formats show the sender's address being the first line of the letter, two lines above the date.
The Recipient's Name and Address
Leaving one line open, the name of the person that the letter is being written to, along with the recipient's title, any suite or room number, the company name and the street address should all be next in the header. U.S. Postal Service standard addressing rules should be applied here if being mailed in the U.S.; or use the rules of the country that the letter is being mailed to if it is going to a recipient outside the United States..
Skip down one line and the name of the recipient should appear here with a salutation such as "Dear Mr. [Name]:" etc. followed by a colon. The salutation ends the heading of the letter and should be immediately followed by an empty line and the body of the letter.