Texas Tax Code - TAX § 151.253. Security:  Requirements

(a) The security required by this subchapter may be a cash bond, a bond from a surety company chartered or authorized to do business in this state, a certificate of deposit, a certificate of savings or U.S. Treasury bond, an assignment of negotiable stocks or bonds that has been approved by the comptroller, or any other security deemed by the comptroller to be sufficient for the payment of taxes imposed by this chapter.

(b) The comptroller shall fix the amount of security required in each case, taking into consideration the amount of tax that has or is expected to become due from the person under this chapter and all other applicable local sales and use taxes and the necessity to protect the state against the failure to pay these taxes.  The maximum amount of security that may be required is the greater of $100,000 or four times the amount of the person's average monthly tax liability.

(c) A bond qualifying under this subchapter must be a continuing instrument and a new and separate obligation for the penal sum named in the bond for each calendar year or portion of a calendar year while the bond is in effect.  The bond must remain in effect until the surety or sureties are released and discharged.