To write an addendum to a letter, write "P.S." Then, write the additional information you did not include in the body of the letter. An addendum to a letter is also known as a postscript.
- Write "P.S."
A postscript is a brief message appended to the end of a letter. The postscript follows the signature. The word "postscript" comes from Latin words "post scriptum," meaning "written afterwards." The abbreviation "P.S." is used to introduce the postscript. The abbreviation may be followed by a colon, but it is not necessary.
- Write the information
The postscript of a letter is used for information that the writer wants to convey to the letter's recipient, but did not include in the main body of the letter, usually because the writer forgot. Write the additional information you wish to tell the recipient of the letter.
- Write additional postscripts
If there is a separate point you wish to make after the first postscript, you may add additional postscripts to the letter. The second postscript is introduced with the abbreviation "P.P.S.," which means "postquam-post-scriptum." The third postscript is introduced with "P.P.P.S.," which means "post-post-post-scriptum," and so on. However, only "P.P.S." has somewhat common usage. Using several postscripts should be avoided, especially in formal letters.