This course is offered by the UNT System Training Office. In this hands-on training, users will walk through the specific elements of the IDT forms and learn how to complete them. What's an IDT? An Interdepartmental Transaction (IDT) is a form which permits departments to reclassify revenues or expenses from one cost center to another.  The purpose of the transaction can be to purchase goods or services, to reclass expenditures, and/or reallocate revenues to different chartstrings.