Idaho Statutes Title 63. Revenue and Taxation § 63-217. Filing of material by mail or private delivery services

(1) Any report, claim, return, statement or other document or payment dealing in any way or in any manner whatsoever with taxation which is required or authorized to be filed or made to the state of Idaho, or to any political subdivision thereof, which is:

(2) If any such report, claim, tax return, statement or other document or payment is sent by United States mail and either registered or certified, a record authenticated by the United States post office of such registration or certification shall be considered competent evidence that the report, claim, tax return, statement or other document or payment was delivered to the state officer or state agency or officer or agency of the political subdivision to which addressed, and the date of registration or certification shall be deemed the postmarked date.

(3) Any reference in this section to the United States mail shall be treated as including a reference to any delivery service designated by the secretary of the United States department of treasury under section 7502 of the Internal Revenue Code. Any reference in this section to a postmark by the United States postal service shall be treated as including a reference to any date recorded or marked as described in section 7502 of the Internal Revenue Code by any designated delivery service.

(4) If the date for filing any such report, claim, tax return, statement or other document or making any such payment falls upon a Saturday, a Sunday, a legal holiday or, in matters arising under chapter 30, title 63, Idaho Code, a holiday recognized by the internal revenue service, such acts shall be considered timely if performed on the next business day.