Tex. Alco. Bev. Code § 11.71

A surety under the bond of a permittee may terminate its liability by giving 30 days' written notice of termination, served personally or by registered mail on the principal and the commission. The surety is discharged from all liability under the bond for any act or omission of the principal occurring after the expiration of 30 days from the date the notice is served. If the principal fails to duly file a new bond in the same amount and with the same conditions as the original bond before the expiration of the 30-day period, his permit shall terminate when the 30-day period expires.