The methods for computing deferral charges described in s. 422.204(1) (a) and (b), Stats., are alternatives and a creditor may elect to use either method to the extent that he or she can apply it to the particular transaction. However, if the transaction is not one to which s. 422.204(1) (a), Stats., could apply, for example, because of irregular payments, then the creditor must compute the deferral pursuant to s. 422.204(1) (b), Stats.
Wis. Admin. Code Department of Financial Institutions DFI-WCA 1.281