(a) Unless otherwise provided, any assessment may be voluntarily prepaid by the owner of the land assessed. When a prepayment is made, the amount prepaid must be applied first to the interest until the first following date on which principal may be paid under the bond, and then to the principal.
(b) Alternatively, a municipality may require that prepayment must be applied first to accrued interest, and then to the difference between interest that will accrue from the date of prepayment until the net principal payment of the bonds, and the rate of interest at which the principal is paid may be invested to earn interest from the date of prepayment until the principal payment date, with any remaining balance to be applied to the principal.