P.R. Laws tit. 21, § 651x
(a) License tax declared in return.—
(1) General rule.— Whenever the amount determined by the person as the license tax levied hereunder or any installment thereof or any part of said amount or installment should not be paid on or before the date prescribed for its payment, interest on the unpaid amount shall be charged as part of the license tax at the annual rate of twelve percent (12%) from the date prescribed for its payment until the same is paid.
(2) When an extension is granted.— Whenever an extension is granted for the payment of the amount so determined as the license tax by the person, or any installment thereof and the amount, the payment date of which was so extended, and the interest thereon determined under § 651y of this title shall not have been fully paid before the extension period has expired, then instead of the interest provided in clause (1) of this subsection, interest at the annual rate of ten percent (10%) on the unpaid amount shall be charged from the date of the expiration of the extension until the amount is paid.
(b) Deficiency.— Whenever a deficiency or any interest or additional amounts assessed in connection therewith under § 651v or under § 651w of this title, or any tax addition provided in § 651u of this title, are not fully paid within ten (10) days following the date of notice and demand by the Finance Director, interest on the unpaid amount shall be charged as part of the license tax, at the rate of ten percent (10%) annually from the date of said notice and demand until the same is paid.
(c) Additional surcharge.— In any case where it is proper to add interest under subsections (a) or (b) of this section there shall be charged besides, as part of the license tax and in the same manner the interest is charged, the following surcharges:
(1) For a delay of thirty (30) days or less in the payment there shall be no charge;
(2) for a delay in excess of thirty (30) days but not exceeding sixty (60) days in the payment, five percent (5%) of the unpaid amount, or
(3) for a delay in excess of sixty (60) days in the payment, ten percent (10%) of the unpaid amount.
This subsection shall not apply in cases where extensions of time have been granted for the payment of the license tax, and compliance is had with the terms thereof.
History —July 10, 1974, No. 113, Part 1, p. 371, § 25; Nov. 17, 1992, No. 93, § 17.