N.J. Stat. § 54:5-58
The amount required to redeem within 10 days from and including the date of sale, unless a tax sale certificate has been duly issued during the 10-day period, shall be the sum paid at the sale, with interest from the date of sale at the rate of redemption for which the property was sold. After 10 days from the date of sale including the date of sale as the first day, or after issuance of the tax sale certificate during the 10-day period, the amount required for redemption shall be that amount plus the expenses incurred by the purchaser as hereinafter provided, and subsequent municipal liens, as provided in sections 54:5-59 and 54:5-60 of this Title. Where, because of municipal fiscal restrictions imposed upon the tax collector, the transmission of the redemption sum to the purchaser is dependent upon the approval of the governing body, or other officer, of the municipality, such interest shall be computed to the time when such governing body or officer may next act with respect thereto.
N.J.S. § 54:5-58