N.H. Rev. Stat. Ann. § 511:10

A creditor attaching his debtor's interest in real estate, whether such interest is a right of redeeming the same upon mortgage or levy or sale on execution or for taxes, or a right to receive a conveyance by virtue of a contract, may, while such right exists, as well before as after the sale thereof on his execution, pay or tender to the person entitled to the redemption of purchase money the sum due him.