Parts of a Letter
Every letter has several parts. Some parts are optional, so not all letters will contain all of the following.

1. Letterhead. Most companies have stationery with the letterhead already printed at the top. A letterhead contains the company name and complete mailing address, but it may also include a design or symbol of the company and other information. If you have no letterhead stationery, type a return address with your street, city, state, and zip code. Do not include your name in the return address.
2. Date. Write out the full month, the day, and the year.
3. Inside address. The inside address should look like the address on the envelope. It contains the name of the person to whom you are writing, the person's title, the company name, and the complete address. Use a courtesy title in front of the name (Mr., Dr., Ms.) as long as the gender of the person is clear.
4. Attention Line (optional). Sometimes a letter is addressed to a company, but an attention line suggests that it is to be seen by a particular person. Usually this is the second line of the inside address, and the word Attention is often followed by a colon before the person's name. Sometimes the attention line is typed two lines below the inside address.
5. Salutation. The salutation always agrees with the first line of the inside address. The usual greeting is "Dear," followed by the reader's courtesy title and the last name ("Dear Ms. Jones"). When a name is not known or when you are writing to a company (even with an attention line), choose either "Dear Sir or Madam" or "Ladies and Gentlemen." The salutation can end either with a colon (mixed punctuation) or with no punctuation (open punctuation).
6. Subject line (optional). A subject line sums up the main message of the letter and is typed two lines below the salutation. A colon may follow the word Subject.
7. Body. The message, which is the body of the letter, begins two lines below the salutation (or the subject line, if used). Paragraphs are usually single-spaced with double-spacing between paragraphs.
8. Complimentary close. The most common closings are still "Sincerely," "Sincerely yours," and "Yours truly." Only the first word of the closing is capitalized. The complimentary close ends either with a comma (mixed punctuation) or with no punctuation (open punctuation).
9. Company line (optional). If a company wishes to include its name, it is typed in all capital letters two lines below the complimentary close.
10. Signature block. Several returns, usually five, are keyed to allow enough space for the writer's signature. Then the person's full name is typed. A courtesy title before the name is optional but it is a good idea to include it if the gender of the writer is unclear from his or her name (for example, Dana, Morgan) or from the initials (such as I.A. Skinner). The writer's title, if short, can follow the name, separated by a comma; or the title can be typed on the line below the person's name.
11. Reference initials. The typist's initials are usually given in lowercase letters two spaces below the signature block. When the writer's initials are included, they are always typed first ("MTL:aer"). Since there are several acceptable styles, follow the company's preference. When the writer types the letter, no reference initials are used.
12. Enclosure. To draw the reader's attention to additional material included with the letter, the word Enclosure or Enc. is typed two lines below the reference initials.
13. Copy line. When copies of the letter are being sent to other people, the reader should know who these people are. The letter c is followed by the name(s). A colon after the c is optional.

Formats for Business Letters

1. Block. Block format is the most popular format used today because it is the easiest to type. All parts of the letter except the letterhead begin at the left margin, with no indentations of any kind. Letter 1 uses block format.
2. Modified Block. Modified block is the most traditional format and is still used. The significant difference in this format is that the date, the complimentary close, and the signature block begin at the center of the page. All other parts begin at the left margin. The first line of each paragraph may be indented five spaces, but this option is not necessary because paragraphs are identified by double spacing. Letter 2 uses modified block format.
3. Simplified style. All parts of the letter start at the left margin, but this untraditional format omits both the salutation and the complimentary close, believing that they serve no real purpose. The reader's name, however, is often included in the body of the letter. A subject line (with or without the word subject) is typed in full capital letters below the inside address. The writer's name and title are usually typed on one line in capital letters below the body. Letter 3 uses simplified style.