RSA 303:13: Redemption.

Each proprietor of lands or rights so sold, his heirs or any person interested therein may redeem the same at any time within one year from the sale thereof, by paying or tendering to the collector, his executor or administrator, or, in his absence, at the usual place of abode of the collector, his executor or administrator, a sum equal to such assessment and the incidental charges of the sale, and interest at the rate of 12 percent per annum thereon from the day of sale, which shall be for the benefit of the purchaser.