Parts of a Business Letter This resource is organized in the order in which you should write a business letter, starting with the sender's address if the letter is not written on letterhead. Sender's Address The sender's address usually is included in letterhead. If you are not using letterhead, include the sender's address at the top of the letter one line above the date. Do not write the sender's name or title, as it is included in the letter's closing. Include only the street address, city, and zip code. Date The date line is used to indicate the date the letter was written. However, if your letter is completed over a number of days, use the date it was finished in the date line. When writing to companies within the United States, use the American date format. (The United States-based convention for formatting a date places the month before the day. For example: June 11, 2001. ) Write out the month, day and year two inches from the top of the page. Depending ...