(a) An employer who does not pay a contribution on or before the date prescribed by the commission is liable to the state for interest of one and one-half percent of the contribution for each month or portion of a month that the contribution and interest payments are not paid in full. The total interest applied may not exceed 37-1/2 percent of the amount of contribution due at the due date.
(b) Liability for interest under Subsection (a) does not apply to an employer who:
(1) failed to pay a contribution because of the bona fide belief that all or some of its employees were covered under the unemployment insurance law of another state; and
(2) paid when due a contribution on all the wages of those employees under that law.