(1) The commissioner may provide for the following by rule and regulation:
(a) Periodic notification to employers of benefits paid and chargeable to their accounts or of the status of such accounts; and
(b) Notification to all base period employers of any individual of the establishment of such individual's benefit year.
(2) Any such notification, in the absence of an application for redetermination filed in such manner and within such period as the commissioner may prescribe, shall become conclusive and binding upon the employer for all purposes. Such redeterminations, made after notice and opportunity for hearing, and the commissioner's findings of fact in connection therewith may be introduced in any subsequent administrative or judicial proceedings involving the determination of the combined tax rate of any employer for any calendar year.