SEC Form 10-KT405 is a form used before the year 2003 under the Securities and Exchange Commission. The purpose of SEC Form 10-KT405 is to substitute SEC Form 10-K405 foe when a company transitions its fiscal year-end. Like SEC Form 10-K405, SEC Form 10-KT405 is used to signify the failure of a company officer or director to file a Form 3 or Form 4 or Form 5 on time. This means that the company was not able to disclose the insider trading activities within the mandated time frame.