N.H. Rev. Stat. Ann. § 80:46

The register of deeds shall be paid by the collector of taxes the following fees: For recording and indexing each parcel advertised to be sold, $1; for recording and indexing a report of payment before sale or redemption after sale or discharge of lien, $1; for recording and indexing a report of tax sale, each parcel sold, $1. The collector of taxes shall be reimbursed for the fees advanced to the register by the person paying the tax before sale, or redeeming the real estate after the real estate has been sold, or requesting the discharge of the tax lien. The register of deeds may make such charge as he deems reasonable and proper for searching the records and reporting mortgage encumbrances at the request of a purchaser at a tax sale; however, this shall not be considered a mandatory duty of the register of deeds.