The majority of official and semi-formal correspondence should be typed. Informal letters can be written by hand. If you are typing your letter, select a 10- to 12-point typeface with single line spacing. Include a one- to one-and-a-half-inch margin around each page. Use paper that is 8 1/2 by 11 inches or larger.
In general, use 14-point type for formal letters, and 10 point type for informal letters. Some people like to use smaller font sizes for informal letters to increase readability. Experiment with different typesizes to find what works best for you.
All-caps text is used to emphasize a particular word or phrase. Unless otherwise specified, all-caps text should be treated as first-line emphasis. Place all-caps words in sentence punctuation marks to ensure that they are not mistaken for beginning sentences or main ideas.
Boldfaced text is used to highlight a section of the letter for emphasis. Beginners should avoid using boldface because it makes reading difficult due to its heavy weight. Use boldface only when necessary.
Italicized text is used to indicate a word or phrase that is important but not essential for understanding the letter. Italics are created by using the tag instead of bold or italicized text.
If you're sending an email, utilize the block structure regardless of formality. Place two-inch margins on all sides of the email unless you receive a formal letter in which case it is acceptable to use a one-and-three-quarter-inch margin.
Alignment and Margins Make use of conventional margins (one-inch margins, usually). Smaller margins (up to 0.7 inch) are acceptable as long as they are uniform on all sides. Align all paragraphs to the page's left. (You may also indent the first line of each paragraph, though this is less common.)
Follow these guidelines to ensure your letter looks professional:
You should use a simple, standard font such as Arial or Times New Roman for business letters, and a font size of 10–12 pt (depending on the font). Even if your letter is short, don't use a large font size to increase the space it takes up on the page-this will look unprofessional.
Professional letters can be written in a variety of styles. Letters are divided into two types: block form and indented form. The examples below can assist you in deciding which style you like. Do note that both styles are acceptable in formal correspondence.
Block form is the most common letter format. It consists of an initial paragraph that states the main point of the letter, followed by additional paragraphs that support or clarify this point. Block letters should not exceed one page in length. An indentation of about 1/4 inch is sufficient to identify separate paragraphs within the text.
Indented letters contain several paragraphs on a single page. Like block letters, they should not go beyond one page in length. However, unlike block letters that use punctuation only at the end of a sentence, indented letters often include small indentations at the beginning of each paragraph to indicate the start of a new thought.
Letters written in block form are easier to read because all the information needed for understanding is included on the same line. This means that readers do not have to scroll down to see what was said earlier in the letter. Letters written in indented form are harder to read because they require scrolling back and forth between pages. Indented letters should not be longer than one page due to reading time issues.