Close Your Letter
A complaint letter should close in a professional manner. Once your last paragraph is written, sign off between a complimentary close such as "Sincerely," or "Thank you," and your printed name.
If you are writing in conjunction with an official duty, place your title below the printed name as in the sample complaint letter. Additional information such as dictation remarks, notification of attachments, enclosures and copies sent to other individuals should be placed beneath the title line.