How to Write a Business Letter

The most common layout for a business letter is known as block format, where the entire letter is left-justified and single-spaced, with a double space between paragraphs. Business letters typically have 1-inch (25.4 mm) margins on all sides of the page.

The generally accepted font is Times New Roman, 12 pt., although other fonts like Arial are sometimes used.

A business letter should be printed on "letter size" paper, which is 8.5" by 11" in size. Outside the U.S., you can use paper size A4. For a lengthier contract, you can use 8.5" by 14" paper, otherwise known as "legal size."

This goes in the top left-hand corner of your page, with each part of the address written on a new line. You should not include your (or the sender's) name or title as you will list that information in the closing.

Leaving an open space after your company information, type out the date in full for a more professional look. If you took a couple of days to write your letter, use the date on which you finished. When writing to a recipient within the U.S., use the American date format: month, day, year.

Leave a line open after the date and add your recipient's full name, title (if applicable), company name, and address. Type out international recipients' countries in capital letters on the last line. Each piece of information should appear, in this order, on a separate line. You may also include a reference number, if necessary.

Finally, and after leaving another line open after your recipient's information, choose an appropriate salutation depending on the person you are writing to, how well you know them, and how formal your relationship is.

Start your letter with a short introductory paragraph. It should include a friendly but professional opening and the main point(s) of the letter.

In a formal yet friendly tone write the body of your letter. The first paragraph can include a friendly opening but should focus on a statement of the main point. The second paragraph should justify the importance of the main point. Each subsequent paragraph should continue the justification with background information and supporting details. The closing paragraph should restate your main point and request action.

Choose an appropriate closing that is an indicator of respect and formality, and use a comma after your closing. Always use a positive closing, with only the first letter capitalized. Sign the letter.

After the signature block, type in your name, title, phone number, email address, and any other appropriate means of communication. Each piece of information should be in its own line. Do not include your company's address as it is at the top of the page.

For any additional documents added to your letter, note the number and type of documents beneath your contact information. For example, "Enclosures (2): brochure, market analysis." This ensures the reader does not miss any important information.

Be sure to check spelling, punctuation, grammar, and professional appearance. You can run spell check but also read through your letter as spell check does not catch all nuances.