The most formal way of signing a letter on behalf of your boss is by using the designation p.p., an abbreviation of the Latin phrase “per procurationem.” Simply put, the initials p.p. before your name indicates that your boss has granted you the authority to make the correspondence on their behalf.

In this case the proxy, or staff member signing on behalf of the boss, should sign her own name with the letters "p.p." before the signature. The name of the boss should be typed out under the signature. The letters "p.p." stand for "per procurationem" which means "through the agency of."

If you don’t know how to sign a letter on behalf of someone else, you can start by using p.p. It stands for per procurationem. It is legally secure and shows that you represent someone else in your letter writing. For instance, you might be writing a letter on behalf of your boss.