Tex. Natural Resources Code § 52.139

(a) If an audit billing notice has been issued under Section 52.135 and any outstanding audit deficiency assessment has been paid either:

(1) voluntarily;

(2) after a hearing was requested and the commissioner has entered a final non-appealable order concerning the assessment; or

(3) after a final non-appealable judgment has been rendered by a court after filing of a suit under Section 52.137, then the commissioner may not issue another deficiency assessment which covers the same issues, time periods, and leases as those covered by the previous assessment.

(b) If the commissioner audits a lessee's books and records under Section 52.135 of this code the commissioner shall notify the lessee upon completion of his findings. If the commissioner notifies the lessee that no additional royalties are due, the commissioner may not again audit the books and records covering the same issues, time periods, and leases involved in the first audit.

(c) This section shall not preclude the commissioner from conducting subsequent audits or examinations covering the same issues, time periods, and leases in cases where fraud exists or where the first audit deficiency assessment results only from an examination of documents, records, or reports submitted to the commissioner and not from a complete audit of the books, accounts, reports, or other records of a lessee.