N.M. Stat. § 59A-45-10
A premium finance agreement may provide for the payment by the insured of a delinquency charge on each installment in default for a period of more than ten days and in an amount not to exceed five percent of each installment, or five dollars ($5.00), whichever is less, or in lieu thereof, interest after maturity of each such installment not to exceed the highest lawful contract rate; except that with respect to agreements financing coverages for other than personal, family or household purposes, the delinquency charge shall be an amount equal to five percent of the unpaid installment, but in no event more than five hundred dollars ($500). In addition, such contract may provide for the payment of an attorney's reasonable fee, where it is referred for collection to an attorney not a salaried employee of the person to whom the installment payment is due, and for court costs and disbursements.
NMS § 59A-45-10