Every financial institution designated as a public depository and holding any deposit of public funds of any depositing unit under the provisions of this chapter shall, on or before beginning to hold such deposits, file with the treasurer and the supervising board of each such depositing unit whose deposit it so holds, the affidavit of one (1) of its officers showing the amount of the capital stock and surplus or reserves and unallocated or undivided earnings, as applicable, of such institution. In the event that such institution has such an affidavit on file with the treasurer and supervising board of each relevant depositing unit on the effective date of this section, such affidavit or affidavits shall satisfy the requirement of this section until January 31 of the year next following the effective date of this act. Such affidavits shall be effective for the purposes of this section to and including January 31 next following the date of their filing, but no longer, and, on or before that date, if such institution is to continue as a designated public depository under this chapter, a like affidavit shall be filed in like manner for the succeeding year on or before the date specified by the state treasurer pursuant to section 67-2739(2), Idaho Code. No such institution shall receive deposits from nor act as depository for the public funds of any depositing unit unless and until an affidavit as is herein required and which still continues in effect is on file with the treasurer and the supervising board of such depositing unit in accordance with this section.