means permitted by the Secretary. (g) Security Requirements A large seller (within the meaning of subsection (e)(3)) shall be required to provide security in an amount equal to the greater of $100,000 or one and one-half times the seller’s average monthly tax liability during the previous 6 calendar months. Security may be a cash bond, a bond from a surety company approved by the Secretary, a certificate of deposit, or a State or United States Treasury bond. A bond qualifying under this subsection must be a continuing instrument for each calendar year (or portion thereof) that the bond is in effect. The bond must remain in effect until the surety or sureties are released and discharged. Failure to provide security in accordance with this section shall result in revocation of the seller’s section 502 registration. If a person who has provided security pursuant to this subsection— (1) fails to pay an amount indicated in a final notice of amount due under this subtitle (within the meaning of section 605(d)), (2) no Taxpayer Assistance Order is in effect relating to the amount due, (3) either the time for filing an appeal pursuant to section 604 has passed or the appeal was denied, and (4) the amount due is not being litigated in any judicial forum, then the security or part of the security, as the case may be, may be forfeited in favor of the Secretary to the extent of such tax due (plus interest if any). (h) Rewards Program The Secretary is authorized to maintain a program of awards wherein individuals that assist the Secretary or sales tax administering authorities in discovering or prosecuting tax fraud may be remunerated. (i) Cross Reference For interest due on taxes remitted late, see section 6601. 502. Registration (a) In General Any person liable to collect and remit taxes pursuant to section 103(a) who is engaged in a trade or business shall register as a seller with the sales tax administering authority administering the taxes imposed by this subtitle. (b) Affiliated Firms Affiliated firms shall be treated