How to Fold a Business Letter. A business letter is a direct representation of your company. Your letter is the first impression your business makes on the recipient. Folding a business letter correctly conveys attention to detail down to the last letter. Follow these basic directions to fold your business letter in a professional way.
Use a Number 10 envelope. The most commonly used envelope for a business letter is the Number 10. Pull the bottom of the letter two thirds of the way up the page and press a crease. The bottom of the letter should be slightly below the address line. Fold the top of the letter so that it's flush with the bottom crease.
Change the fold for a Number 10 envelope with a window. You must modify the fold when using a Number 10 envelope that has a window. First, line the bottom of the envelope across the letter one third of the way down from the top and crease it. Then turn the letter over and pull the top of the letter down toward you with the writing facing you. When creasing, the folded letter should resemble the letter z.
Fit your business letter in a Number 6 ¾ envelope. Place the bottom of the letter one half to one inch from the top of the letter. Begin at the right side and fold the edge one third of the way toward the center. Fold the left side of the letter so that it crosses over the last fold and is flush with the edge of the letter.
Fold for a Number 55 envelope. There are two acceptable ways you can fold a business letter for a Number 55 envelope. The first is to repeat Step 1. You can also fold the business letter in half so that the top and bottom edges are flush and the writing is folded into the center.
Watch out for paper cuts.