Utah Code § 54-8-21
The governing body may in the resolution levying the assessments provide that all unpaid installments of assessments levied against any piece of property may (but only in their entirety) be paid prior to the dates on which they become due if the property owner paying such installments pays all interest which would accrue thereon to the next succeeding date on which interest is payable on the bonds issued in anticipation of the collection of the assessments, together with such additional amount of interest as in the opinion of the governing body is necessary to assure the availability of money fully sufficient to pay interest on the bonds as interest becomes due and any redemption premiums which may become payable on the bonds in order to retire in advance of maturity bonds in a sufficient amount to utilize the assessments thus paid in advance. If no bonds have been issued then all unpaid installments of assessments levied against any piece of property may be paid in their entirety prior to the date upon which they become due by paying the principal amount due and the interest accrued thereon to the date of payment.
Utah Code § 54-8-21