(b) If a change in a classification assignment on a workers’ compensation insurance policy is due to an erroneous classification and results in an increased premium, the classification change shall become effective on the effective date of the erroneous classification assignment provided any of the following conditions occur:

1. (1) The revised classification assignment is published within three months of the effective date or publication date of the erroneous assignment.
2. (2) The insurer or, where applicable, the designated rating organization, was notified in writing within three months of the effective date or publication date of the erroneous classification assignment of a possible error.

3. (3) The designated rating organization notified the insurer in writing within three months of the effective date or publication date of the erroneous classification assignment that the erroneous classification assignment was under review.

   If one or more of the conditions set forth in paragraphs (1), (2), and (3) do not occur, the revised classification assignment shall become effective as of the date it is published unless the publication date is less than three months prior to the expiration date of the outstanding policy, in which case the revised classification assignment shall become effective as of the inception date of the policy that replaced the outstanding policy.