Liability under operations bonds, withdrawal bonds, and unit bonds may be terminated for future withdrawals, future production, or future deposits as set forth below:
(a) On application by the surety. A surety may terminate a bond by filing a notice as provided in Sec. 19.171;
(b) By replacement of the bond. A principal may terminate an existing bond by replacing it with a superseding bond approved by TTB;
(c) By discontinuing withdrawals. A principal may terminate a withdrawal bond by notifying TTB that the principal has stopped making withdrawals covered by the bond, if the bond was filed solely as a withdrawal bond; or
(d) By discontinuing the business. A principal may terminate a bond by notifying TTB that the principal has discontinued business. (26 U.S.C. 5173)