The block-style letter uses a minimalist format with no indents; every part of the letter starts at the left margin. The most formal of the business letters, the block-style format avoids the use of fanciful fonts and spacing, allowing the reader to focus on the content. This is the best form to use if you want to convey a serious and respectful tone.
Sender's Address and Date
The block-style format uses 1-inch margins all around. Everything in the letter is typed flush left. The only exception is when the letter is written on letterhead. In this case, the letterhead is printed at the top and generally centered. Letters that are not written on letterhead begin with the sender's address and relevant information, such as phone and fax number, below the address. Do not include the sender's name or title in this section. The next section is the date. Skip two spaces after the letterhead or one space after the sender's address; this provides visual space between sections. The date should be located approximately two inches from the top of the page. Spell out the date completely, beginning with month, day and year. For example, January 31, 2006, would be correct. Skip a space after the date.
The recipient's information begins two lines below the date. This includes the name, title, address and phone number of the person reading the letter. Use Mr., Mrs., Ms. or Dr. before the recipient's full name. Underneath the name, include the person's title, if relevant. Type the complete address, phone number and email. Research any information that may be missing to complete this section thoroughly and accurately. Avoid abbreviations if possible.
Salutation and Body
Skip a line after the recipient's information and compose a salutation or greeting. A formal salutation begins with the word "Dear" and is followed by the first and last name of the recipient and then a colon. The block-format letter errs on the formal side; when in doubt, it is best to use a title, such as Mr., Mrs., Ms. or Dr. along with the first and last name. If the recipient is a good friend or associate, using their first name may be acceptable. Following the greeting, skip a line and begin the body of the letter. Paragraphs should not be indented. Instead, double-space between paragraphs. This is not the time to focus on creative embellishments. Stick to 12-point font that does not divert attention from the message of the letter. New Times Roman is an acceptable font.
Once you have completed the letter, skip a space and insert a closing. The word "Sincerely" followed by a comma is conventional. Triple space after the closing and type the sender's name and title underneath it. This triple spacing allows you, the sender, to sign your name after the letter is printed. If there are enclosures, such as a resume or other documents, skip a space after your name and title and type the word "Enclosures." Follow this with the number of enclosures in parenthesis, such as "Enclosures (3)." If the letter is typed by someone other than yourself, include the person's initials in lowercase print one skipped space below your name or "Enclosures." If copies are to be sent to other parties, include those names by skipping a space and typing "cc:". After the colon, list names vertically, one per line. Use "cc:" one time only.
Differences From Other Styles
The characteristic that distinguishes the block-style format from other letter formats is the lack of indentation. For example, in the modified block style, the date, sign-off and signature line are centered, and the beginning of each paragraph is indented. In the semi-block style, all elements are aligned to the left margin except the beginnings of the paragraphs, which are indented. An extra space is added between the paragraphs, just like the block style.