An obsolete Securities and Exchange Commission (SEC) form that was submitted in lieu of a 10-K405 when a company changed its fiscal year-end. SEC Form 10-KT405, and the 10-K405, were used by the SEC prior to 2003. The form was used when a company was not punctual in filing a Form 4 (or similar Form 3 or Form 5) disclosing its insider trading activities.

Guidelines for reporting insider trading activity is covered under Section 16 of the Securities Exchange Act. SEC Forms 10-K405 and 10-KSB405 were eliminated after it was determined that the use of forms was inconsistent and unreliable. The form is no longer accepted by the EDGAR system.