Business Letter Writing Guidelines. Here are guidelines for writing a business letter, so all your correspondence makes the best impression. Margins: Business letter margins should be about 1" all around. This gives your professional letter an uncluttered look. You should align your text to the left; this is how most documents are aligned, so it will make your letter readable. Letter Spacing: Leaving space in your letter creates a clear, uncluttered and easy to read look that the reader will appreciate. Your letter should be in block format: the entire letter should be aligned to the left and single_spaced except for a double space between paragraphs.
It is established etiquette by the Joint Chiefs of Staff, United States Department of Defense, the U.S. Army, the U.S. Navy, and the U.S. Air Force that the closing “Respectfully yours” be reserved for the President of the United States (according to U.S. Army standards, this also extends to the first lady and the President_elect).