Texas runs one of the most active sales tax audit programs in the country, and the Comptroller of Public Accounts has been particularly aggressive about it in recent years. If you've received a Notice of Routine Tax Audit from Texas, or you're worried you might, understanding the actual process, and where businesses most often go wrong, makes a real difference in the outcome.
How a Texas Audit Starts
The process typically begins with a formal Notice of Routine Tax Audit, sent by certified mail. It identifies the tax types under review (usually sales and use tax together, since Texas audits both in the same engagement), the reporting periods covered, and the auditor assigned to your case.
Alongside the notice, you'll receive an Audit Questionnaire, which asks about your accounting software, business locations, and key personnel. This questionnaire typically needs to be completed and returned within 30 days, and it becomes part of your permanent audit file, so accuracy matters from the very first step.
The Four-Year Statute of Limitations, and Its Exceptions
Texas generally has four years from the date a tax became due to assess a deficiency. That's the standard rule, and it's why most Texas audits reach back roughly four years from the notification date.
But that four-year window disappears entirely in three situations:
- You filed a false or fraudulent return with intent to evade tax
- You didn't file a required return at all
- Your return contained a "gross error," defined as underreporting tax by 25 percent or more
In any of these cases, the Comptroller can assess tax, penalties, and interest with no time limit at all. If your records are thin enough that the auditor can't rule out a 25 percent understatement, you're not just risking a bigger bill for the periods in front of you, you're risking an open-ended lookback.
You may also be asked to sign a statute waiver, extending the standard period, usually to give both sides more time to work through documentation or sampling disputes. Signing one isn't automatically a bad idea, but it's a decision worth making deliberately, with guidance, rather than as a routine courtesy to keep things moving.
Sampling: Why the Auditor Doesn't Review Everything
Texas has statutory authority to use sampling when records are too voluminous for a full review, when records are inadequate, or when a complete review would cost more than it's worth relative to the likely result. In practice, that means the auditor selects a sample period, usually a few months out of the full audit window, examines it in detail, calculates an error rate, and projects that rate across the entire period under audit.
This is why a handful of problem transactions in the sample period can carry consequences far beyond their own dollar value. If you can demonstrate that a specific transaction in the sample isn't representative of your normal operations, it's possible to have it pulled from the sample and assessed separately rather than projected across the whole period, but that requires catching it and raising it, not assuming the auditor will.
The Managed Audit Alternative
Texas offers a Managed Audit Program, where you conduct a structured self-review under Comptroller supervision rather than a traditional fieldwork audit. If completed successfully with no fraud found, Texas may waive all penalties and a significant portion of interest.
A few things to know if you're considering it: you generally need to request it within 60 days of your Audit Notification Letter, it requires you to be current on filings with a clean compliance history, and it comes with its own statute waiver, typically extending the audit period 90 days beyond the completion timeline. It gives you more control over pacing and can meaningfully reduce penalty exposure, but it also comes with strict documentation and timeline requirements that aren't a good fit for every business.
What Auditors Focus On
Certain patterns tend to draw more scrutiny in a Texas audit:
- High exemption volume. If a large share of your sales are exempt, expect the auditor to want to verify every certificate behind that percentage.
- Inconsistent reporting. A significant, unexplained swing in reported sales or tax collected tends to invite questions.
- Prior audit history. A previous audit that turned up meaningful underreporting, especially assessments over roughly $10,000, tends to trigger a faster follow-up audit than the general random-selection cycle.
- Exemption certificate documentation. Expired or incomplete exemption certificates are one of the most common, and most avoidable, sources of assessment.
Exit Conference and Your Options If You Disagree
Once fieldwork wraps up, the auditor presents findings at an exit conference, and the audit goes through internal supervisory review before a formal Notification of Results is issued. If you disagree with the results and haven't paid, you can request an Independent Audit Review, an informal conference with an impartial Comptroller employee who wasn't involved in the audit, to try to resolve disagreements before the matter moves into formal hearings. To contest an assessment without paying first, a Statement of Grounds outlining the disputed items needs to be submitted by the deadline stated in your Notification of Results, so this isn't a step to leave until the last minute.
What to Do If You're Facing a Texas Audit
- Respond to the Audit Questionnaire accurately and on time. It becomes part of your permanent file, so treat it with the same care as the return itself.
- Get your exemption certificates in order before fieldwork starts, not during it. This is consistently one of the most common sources of avoidable assessment.
- Think carefully before signing a statute waiver. Understand what you're extending and why before agreeing.
- Have your dispute file ready before the exit conference, not after. If you're planning to challenge sampling or specific findings, the groundwork needs to be in place early.
- Consider whether a Managed Audit makes sense if you're confident in your compliance but want more control over the process and better odds on penalty relief.
Texas audits move fast, and they're documentation-driven in a way that rewards preparation over improvisation. If you've received a notice or think you may be a target, The Sales Tax People can help you get ahead of it before fieldwork begins.
People Also Ask:
A Texas sales tax audit begins with a formal Notice of Routine Tax Audit sent by certified mail from the Comptroller of Public Accounts. The notice identifies the tax types under review — typically sales and use tax together, since Texas audits both in the same engagement — the reporting periods covered, and the auditor assigned to the case. Alongside the notice, you will receive an Audit Questionnaire (Form 00-750) asking about your accounting software, business locations, and key personnel. This questionnaire must be completed and returned within 30 days, and it becomes part of your permanent audit file. Accuracy matters from the very first step: errors or inconsistencies in the questionnaire can create problems that follow the audit through fieldwork, exit conference, and any subsequent dispute. The auditor then schedules an entrance conference to outline the audit plan and timeline before fieldwork begins.
Texas generally has four years from the date a tax became due to assess a deficiency — which is why most Texas audits cover roughly four years from the notification date. However, this four-year window disappears entirely in three situations: if you filed a false or fraudulent return with intent to evade tax; if you failed to file a required return at all; or if your return contained a gross error, defined as underreporting tax by 25 percent or more. In any of these cases, the Comptroller can assess tax, penalties, and interest with no time limit whatsoever. If your records are thin enough that the auditor cannot rule out a 25 percent understatement, you are not just risking a larger bill for the periods in front of you — you are risking an open-ended lookback. The auditor may also ask you to sign a statute waiver extending the standard period, typically to allow more time for documentation or sampling disputes. Signing one is not automatically a bad idea, but it is a decision worth making deliberately, with professional guidance.
The Texas sales tax audit questionnaire — officially Form 00-750 — is one of the first documents the Comptroller sends alongside the audit notice. It asks about your corporate structure, accounting software, point-of-sale systems, business locations, and key personnel responsible for sales tax compliance. You generally have 30 days to complete and return it, and it becomes part of your permanent audit file — meaning the auditor, and anyone reviewing the audit later, will reference it throughout the engagement. This is not a form to fill out quickly or casually. The answers establish how you describe your business operations to the state, and inconsistencies between your questionnaire responses and what the auditor later finds in your records create credibility problems that are difficult to walk back. Before completing the questionnaire, understand what the audit period covers and consult a professional if there are any aspects of your operations — exemption practices, sales channel complexity, prior audit history — that require careful framing.
Texas has statutory authority to use statistical sampling when records are too voluminous for a full review, when records are inadequate, or when a complete review would be disproportionately costly relative to the expected result. In practice, the auditor selects a sample period — typically a few months out of the full audit window — examines it in detail, calculates an error rate, and projects that rate across the entire period under audit. This is why a handful of problem transactions in the sample period can carry consequences far beyond their own dollar value: a 15 percent error rate in a sample projected across three years of transactions can produce a very large assessment. If you can demonstrate that a specific transaction in the sample is not representative of your normal business operations, it is possible to have it pulled from the sample and assessed separately rather than projected across the entire period — but that requires catching the issue and raising it proactively, not assuming the auditor will identify it themselves.
The Texas Managed Audit Program is an alternative to a traditional fieldwork audit in which the business conducts a structured self-review of its own records under Comptroller supervision. If the managed audit is completed successfully and no fraud is found, Texas may waive all penalties and a significant portion of interest — making it one of the most penalty-favorable options available to any business facing a Texas audit. Several conditions apply: you generally need to request the managed audit within 60 days of your Audit Notification Letter, your business must be current on all filings with a clean compliance history, and the program comes with its own statute waiver extending the audit period 90 days beyond the completion timeline. It gives the business more control over pacing and significantly improves penalty outcomes — but it also comes with strict documentation and timeline requirements that are not a good fit for every business, particularly those whose records are incomplete or whose compliance history has gaps.
Texas audits are initiated through a combination of random selection and specific risk-based triggers. Common triggers include a high volume of exempt sales as a percentage of total revenue, which invites scrutiny of whether every certificate behind that exemption percentage is valid; significant unexplained swings in reported sales or tax collected, which the Comptroller treats as a signal of possible misreporting; prior audit history, particularly any previous assessment over approximately $10,000, which tends to trigger a faster follow-up audit than the general selection cycle; discrepancies between reported sales tax and data from third-party sources such as marketplace platforms, payment processors, or federal income tax returns; and industry-specific risk factors — construction companies, auto dealers, businesses serving alcohol, and SaaS companies all face heightened audit scrutiny in Texas. With over 60 new local rate changes taking effect in January 2026 and more than 900 local jurisdictions, multi-location businesses shipping across Texas are also increasingly flagged for under-collection of local rates.
If you disagree with the audit results, you have several options — but timing is critical at every stage. Before a formal assessment is issued, you can raise disputes at the exit conference and during the supervisory review period that follows fieldwork. Once the Notification of Results is issued, you can request an Independent Audit Review — an informal conference with an impartial Comptroller employee who was not involved in the audit — to try to resolve disagreements before the matter moves into formal hearings. To contest an assessment without paying it first, you must submit a Statement of Grounds outlining the disputed items by the deadline stated in your Notification of Results — missing this deadline forfeits your right to protest without payment. If disputes remain unresolved, the matter can be escalated to an Administrative Law Judge hearing, and ultimately to district court if necessary. Throughout this process, Texas is deadline-driven in a way that rewards preparation — every stage has a defined response window, and missing any one of them significantly limits your options at the next.
