Minn. Stat. § 281.325: CANCELLATION OF CERTIFICATES ON REQUEST OF HOLDER.

Upon request of the holder of a real estate tax judgment sale certificate, state assignment certificate, or forfeited tax sale certificate and surrender of the same, whether notice of expiration of time of redemption has been issued and served or not, the county auditor shall cancel the same, making an entry in the proper copy real estate tax judgment book, opposite the description of land covered by the certificate, "canceled by surrender of certificate."