(1)    General. A contributing milk contractor shall pay an annual fund assessment for each license year, including an assessment for deferred payment contracts entered into under s. 126.485, in the amount specified by the department by rule.

   (5m)   Reduced assessment for certain milk contractors filing security. If a contributing milk contractor files security under s. 126.47 (1) (b), the contributing milk contractor’s fund assessment is the amount specified under sub. (1) reduced by an amount determined as follows:

      (a)    Divide the amount of security that the milk contractor is required to file under s. 126.47 (3) (b) by the amount of the milk contractor’s estimated default exposure.

      (b)    Multiply the amount specified under sub. (1) by the amount determined under par. (a).

   (6)   Quarterly installments.

      (a)    A contributing milk contractor shall pay the milk contractor’s annual fund assessment in equal quarterly installments that are due as follows:

         1.    The first installment is due on June 1 of the license year.

         2.    The 2nd installment is due on September 1 of the license year.

         3.    The 3rd installment is due on December 1 of the license year.

         4.    The 4th installment is due on March 1 of the license year.

      (b)    A contributing milk contractor may prepay any of the quarterly installments under par. (a).

      (c)    A contributing milk contractor who applies for an annual license after the beginning of a license year shall pay the full annual fund assessment required under this section. The milk contractor shall pay, with the first quarterly installment that becomes due after the day on which the department issues the license, all of the quarterly installments for that license year that were due before that day.

      (d)    If s. 126.45 (1) (b) requires a licensed milk contractor to become a contributing milk contractor during the license year, the milk contractor shall pay only those quarterly installments that become due after the requirement takes effect.

      (e)    A contributing milk contractor who fails to pay the full amount of any quarterly installment when due shall pay, in addition to that installment, a late payment penalty of $50 or 10 percent of the overdue installment amount, whichever is greater.

   (7)   Notice of annual assessment and quarterly installments. When the department issues an annual license to a contributing milk contractor, the department shall notify the milk contractor of all of the following:

      (a)    The amount of the milk contractor’s annual fund assessment under this section.

      (b)    The amount of each required quarterly installment under sub. (6) and the date by which the milk contractor must pay each installment.

      (c)    The penalty that applies under sub. (6) (e) if the milk contractor fails to pay any quarterly installment when due.