California CDTFA Sales Tax Appeals: What Happens After the Audit Closes

You opened the letter and saw the number on a California Department of Tax and Fee Administration’s Notice of Determination. Aside from temporarily stopping your heart, this notice signals that the audit has closed and CDTFA has decided what it thinks you owe. Maybe it is $64,000, $230,000, or possibly even higher. Whatever the figure is, it does not feel real for about the first sixty seconds. Then it does.

That number is a position, not a verdict.

Our firm has represented California businesses at every stage of this process, from the first audit notice through hearings before the Office of Tax Appeals. The assessment CDTFA issued represents the agency’s conclusion based on the records it reviewed, the methodology it chose, and the assumptions it made. Every one of those elements can be challenged. Cases get resolved. Assessments get reduced. The number on your Notice of Determination is where the fight begins, not where it ends.

Under Revenue and Taxation Code § 6561, you have 30 days from the date of service of the Notice of Determination to file a petition for redetermination with CDTFA. Thirty days. If that window closes without a petition filed, the determination becomes final. A final determination is a different problem, with different options and significantly less room to negotiate. Everything in this article is about what happens before that clock runs out.

What the Notice of Determination Actually Is

The Notice of Determination is CDTFA’s written conclusion after the audit closes. It sets out the additional tax the agency believes you owe, any penalties, and interest. What it does not tell you is how the auditor got there: what methodology was used, how the sample was drawn, or which of your transactions got flipped to taxable. That is the starting point for the challenge.

This is not a final bill. It becomes final only if you do nothing. The 30-day window under Revenue and Taxation Code § 6561 exists because auditors make errors and the legislature knew it.

The date on the notice is what starts the clock. Not when you opened it. Not when you called your accountant. I have had clients reach me with fewer than five days left. Those calls are harder. Contact Sales Tax Legal before the window closes.

The 30-Day Petition: What It Does and Why It Matters

The 30 days is a critical and hard deadline. Most cases should be appealed even if just for penalties and a payment plan. Filing the petition for redetermination is how you preserve your appeal rights. It goes directly to CDTFA, puts the agency on notice that you are contesting the assessment, and opens the door to a proceeding where you can actually be heard.

The petition should identify the specific grounds on which the determination is incorrect: the sampling methodology was not representative of your actual operations, specific transactions were misclassified, or the audit period selection was inappropriate. Your attorney builds the record here that travels forward to every subsequent stage. Under Revenue and Taxation Code § 6562, if you request an oral hearing in the petition, CDTFA must grant it. Request it. It puts your arguments in front of a real person.

Appeals officers have much more authority to settle than auditors do. Auditors assess. Appeals officers can resolve. You can raise legal arguments at this stage that the auditor would never have engaged with. They can apply common sense to a set of facts that produced an unreasonable number and reach a resolution that reflects the actual dispute. I have seen cases headed to a full OTA hearing settle at redetermination because the presentation was organized and the arguments were specific. Having experience in California matters because it gives you a sense of which arguments CDTFA will accept and which are wasteful. You have to know the procedure, the law, and the audience.

Why the Number Is Worth Challenging

The assessment did not emerge from a neutral accounting of your transactions. It emerged from a methodology that is efficient for the state, not necessarily accurate for your specific business.

CDTFA auditors routinely use statistical sampling: they examine a subset of your transactions, calculate an error rate, and project that rate across the entire audit period. The result has the appearance of precision and the reality of approximation. The sample period selection, the population of transactions used, the definition of what constitutes an error, and the extrapolation calculation are all areas where auditors make choices that can be contested. Where CDTFA pulled its sample from an anomalous quarter, the projected assessment can be several times larger than a representative period would have produced.

Beyond sampling, some assessments rest on the auditor’s call that specific transactions were taxable when you treated them as exempt. Wholesale sales with exemption certificates, sales for resale, exempt services, manufacturing exemptions: these are all categories where auditors and taxpayers regularly disagree. Each disputed transaction is an argument on its own terms with the evidence specific to that transaction. The audit period itself is also contestable. If CDTFA selected a period that was statistically advantageous rather than representative of how your business actually operates, that is a challenge worth building a record on.

If the Window Has Already Closed

If the 30 days passed without a petition, the situation is harder but not hopeless. There are informal ways to try to get it reopened depending on the circumstances and the relationships in place. It is a long shot, it does not always work, and you have little leverage going in. The other path is to pay the assessment and file a refund claim under California law, which technically preserves the right to litigate the underlying dispute. In practice that is not realistic for most businesses facing a serious audit assessment.

Once the determination is final, CDTFA can move to collect. That means liens against business and personal assets, bank levies, and license revocations. Penalties compound. Interest accrues. The number does not get smaller because time passes.

The business owner who calls on day three has a full set of options. The one who calls on day 32 is starting without leverage, without the procedural record the petition would have built, with considerably fewer tools. There is no second 30-day window. The statute does not care that you did not understand the deadline. The window opens the day the notice is served and closes 30 days later.

The Three-Level Appeal Structure

If the redetermination proceeding does not resolve the matter, the California appeal structure has additional levels. Each one matters, and the record built at each earlier stage travels forward.

The redetermination proceeding is an internal CDTFA process. You are presenting your case to people who work for the same agency that audited you. Cases with clear documentation errors, significant sampling flaws, or well-documented exemptions tend to resolve here. Cases that turn on contested legal questions about taxability often do not.

The Office of Tax Appeals is where the case goes if it does not resolve at CDTFA. The OTA was established by the Taxpayer Transparency and Fairness Act of 2017 specifically to give taxpayers access to a neutral body outside the agency that assessed them. The panel is composed of tax experts with no connection to CDTFA. OTA appeals are filed through the Office of Tax Appeals Portal at appeal.ota.ca.gov, or by mail or fax, and are heard in Sacramento, Fresno, and Los Angeles. The OTA requires a jurisdictional document from CDTFA, specifically the decision on your redetermination petition, before it can accept a filing. That is why the petition stage cannot be skipped.

An active, well-maintained appeal through CDTFA and the OTA can run for years. For a business managing cash flow and trying to stay operational while a large liability is in dispute, that timeline is a tool, not a failure. During active appeal, the assessment is not final, collection is generally constrained, and the negotiating table stays open.

Under Revenue and Taxation Code § 7093.5, CDTFA also has legal authority to settle civil tax matters in dispute during the protest and appeal process. Most California businesses do not know this option exists. Whether it applies depends on the facts, the strength of the available defenses, and the stage of proceedings. Contact our team to discuss whether your assessment is a candidate for negotiated resolution.

A Recent Case

I represented a restaurant that came in with what looked like a routine audit. It was not routine. The audit started with a standard three-year lookback under Revenue and Taxation Code § 6487. CDTFA then alleged fraud, which triggered an eight-year lookback instead. The assessment went to approximately $500,000: additional tax on the extra years plus a fraud penalty on top.

A fraud finding requires actual evidence of fraudulent intent, not underreporting. What I see in practice is that auditors sometimes reach for the fraud classification based on underreporting alone, as if the underreporting itself proves intent. That is circular. Every assessment finds that more was owed than was paid. That is what an assessment is. CDTFA did not have fraud intent proof. They had an assessment that used the fraud label to expand the audit period and the liability.

We challenged the finding directly, presented the evidence methodically, and eliminated the fraud classification. The eight-year lookback went with it. The assessment collapsed back to the standard three-year period and the client saved hundreds of thousands on the tax and the fraud penalty. The business stayed open.

Knowing which arguments to make and how to build them with precision is what changes the outcome. A last-minute petition with no substance rarely moves the needle. An organized, evidence-based challenge that addresses the specific errors CDTFA made is what appeals officers and OTA panels respond to.

What to Do Right Now

Note the exact date on your Notice of Determination. That is day one. The petition window runs 30 days from service of the notice.

Do not call CDTFA to negotiate informally. It does not pause the clock and can create a record that complicates your position later.

Do not pay as a first move. Paying changes the legal posture of the case. Discuss it with an attorney before writing a check.

Gather the audit workpapers if you have them. They are the record of what the auditor did: the sampling methodology, the transactions examined, the adjustments made. If you do not have them, we can help obtain them.

Call before the deadline. Every day of delay is leverage you cannot recover. Contact Sales Tax Legal for a free consultation.

Frequently Asked Questions

What is a CDTFA Notice of Determination, and how is it different from the audit notice I received earlier?

The audit notice was a request to examine your records. The Notice of Determination is CDTFA’s conclusion after that examination: the amount of additional tax the agency believes you owe, with any penalties and interest. It is the end of the audit phase and the beginning of the appeal phase. You have 30 days from service to file a petition for redetermination if you disagree.

How do I file a petition for redetermination with CDTFA?

The petition is filed directly with CDTFA, not with the Office of Tax Appeals. It should identify the specific grounds on which you believe the determination is incorrect. Under Revenue and Taxation Code § 6562, if you request an oral hearing in the petition, CDTFA is required to grant it. We file petitions as part of our California appeal representation and recommend against filing without counsel in contested cases.

What happens to my 30-day deadline if I need more time to gather evidence?

The 30-day period under Revenue and Taxation Code § 6561 is statutory and does not extend because you are still gathering records. The petition can be filed to preserve rights before the full evidentiary record is assembled, but it must be filed within the window. Talk to an attorney before the deadline, not after.

What is the Office of Tax Appeals, and why is it different from CDTFA?

The OTA is an independent body created by the Taxpayer Transparency and Fairness Act of 2017 to hear appeals outside CDTFA and the Franchise Tax Board. The panel is composed of tax experts who do not work for CDTFA. Appeals are heard in Sacramento, Fresno, and Los Angeles. You must complete the CDTFA redetermination process first before the OTA can accept your filing.

Can CDTFA actually negotiate the amount of my assessment?

Yes. Under Revenue and Taxation Code § 7093.5, CDTFA has authority to settle civil tax matters in dispute during the protest and appeal process. Settlements are not available in every case. Whether a specific assessment can be resolved through negotiation depends on the strength of the available defenses, the factual record, and the stage of proceedings.

What happens if I do not file a petition within 30 days?

Under Revenue and Taxation Code § 6561, the determination becomes final. Once final, CDTFA can pursue collection including liens and levies. The options available after finalization are materially different from those available during the appeal process.

How long does CDTFA have to audit me, and can they come back for prior years?

Under Revenue and Taxation Code § 6487, CDTFA generally has three years from the end of the quarterly period or the return filing date, whichever is later. Failure to file extends that to eight years. Fraud carries no fixed statutory limit.

Do I need a California sales tax attorney, or can my CPA handle a CDTFA appeal?

A CPA can be valuable for organizing records and analyzing the financial substance of disputed transactions. But CDTFA appeal proceedings are legal proceedings. The decisions about argument framing, issue selection, evidence production, and record preservation carry lasting legal consequences. California sales tax appeal work is specialized. It benefits from an attorney who has handled CDTFA assessments specifically, not general tax experience. You can review how we approach California matters on our attorneys page.