52. The credit charges must be computed at the end of a payment period by multiplying the credit rate applicable under section 83 of the Act by the balance of the capital outstanding at the commencement of that payment period and, where applicable, of the credit charges outstanding at the commencement of that period, and by multiplying the product thus obtained by the fraction represented by the payment period in relation to 365.
However, a merchant may exact credit charges that are less than those computed in accordance with the first paragraph.
R.R.Q., 1981, c. P-40.1, r. 1, s. 52.