To include two or more signatures on a business letter, the writer should use the plural voice where appropriate and provide two or more spaces for signatures. Signatures may be listed vertically or horizontally, and they should be ranked by seniority.
When writing a business letter that has two or more signatures, it is important that the person composing the letter remembers to write in the plural. For example, use "we" instead of "I" when offering an opinion or statement that comes from all the parties signing the letter.
After writing the body, the writer can leave space on one line for all signatures by placing a signature line at the left margin and tabbing across to create lines for the other signatures. Another method is to place one or more signature lines under the first, leaving at least two blank lines between signature lines. The name of each person signing the letter should be printed under the assigned signature line.
The signature of the most senior person should always come first, and subsequent signatures should follow in order of decreasing seniority. If the writer is only using one line, the senior person signs on the left, and the others sign on the right. If signing on separate lines, the senior person signs on the top line, while the others sign on the lines below.