California CDTFA Audit Notice: What to Do in the First 72 Hours

The notice does not have a number on it. That is the first thing that surprises most of the California business owners who call our firm. They received something from the California Department of Tax and Fee Administration, and they expected the worst: an assessment, a demand, a dollar figure they would have to argue against. Instead they got a letter. A letter saying CDTFA wants to examine their records. A letter that reads, on the surface, like a professional request for cooperation.

That is exactly what makes it a trap.

The absence of a number does not mean the situation is less serious. It means the number has not been set yet. What you do, or do not do, in the next 72 hours has a direct effect on what that number turns out to be.

Our team has represented California businesses at every stage of a CDTFA audit, from that first notice through hearings before the Office of Tax Appeals. I have watched the same pattern repeat across industries and audit types. The businesses that get the worst outcomes are not the ones who did the worst things. They are the ones who cooperated first and asked questions later.

Before you respond to anything, read this.

What the CDTFA Audit Notice Actually Means

CDTFA administers California’s sales and use tax. That distinction matters. CDTFA is not the Franchise Tax Board. FTB handles income taxes. If you received a notice from CDTFA, the question on the table is whether you collected, reported, and remitted the correct amount of sales tax on your California transactions, and whether you owe use tax on purchases where sales tax was not collected. Your income, your deductions, your federal return are not what CDTFA is looking at.

When CDTFA opens an audit, it issues a written notification as described in CDTFA Publication 76: Audits. That notice tells you that an auditor has been assigned to examine your records. It does not tell you what they think you owe. It tells you that the process of determining what they think you owe is beginning.

What Triggers a CDTFA Audit

Audits are not random. Industry selection, deviation from industry averages, returned check activity, consumer use tax leads, and referrals from other agencies are all common triggers. Restaurants, auto dealers, contractors, and retailers are audited at higher rates than other industries because those sectors have historically produced large adjustments. A spike in your reported exempt sales relative to prior periods is another red flag. If you are in a targeted industry and your numbers are unusual, the probability of audit is higher than you might think.

What They Are Looking For Before They Have Told You

Before the auditor makes a single request, they have already reviewed your registered filing history, compared your reported sales against industry benchmarks, and identified the periods they want to examine. The initial records request, the Information Document Request (IDR), will feel routine. It is not.

The IDR defines the universe of documents the audit will be built on. What you include, exclude, or produce without context shapes the entire trajectory of the case.

The Cooperation Trap

Your instinct is to cooperate. That instinct is understandable, and it is what CDTFA is counting on.

I want to be clear about something: cooperation itself is not the mistake. The mistake is unmanaged cooperation. Business owners who receive CDTFA audit notices routinely call the auditor, explain their business, hand over years of records beyond what was requested, and offer interpretations of their own bookkeeping that they think will help. Those same interpretations help CDTFA build a larger assessment than it would have reached on its own.

The auditor assigned to your case works for CDTFA. That is not a personal criticism of any individual auditor. It is a structural reality that shapes every interaction. Their job is to assess additional tax. Understanding that clearly, before you make any contact, is the most important thing I can tell you.

What the IDR Actually Authorizes

The IDR asks for specific documents for a specific period. That is the scope. Anything you produce beyond that scope is a gift. I have seen clients hand over invoices, contracts, and internal spreadsheets that were never requested, thinking transparency would demonstrate good faith. What it demonstrated was that the audit period could be expanded. CDTFA auditors are trained to use everything that is produced. They do not ignore documents because they were not asked for.

What Happens When You Produce More Than Asked

Scope expands and the period extends. The initial audit window becomes the foundation for looking at adjacent periods. I have had clients who handed over three years of records when the IDR asked for one, and watched the audit grow from a manageable single-period review into a multi-year examination. Every extra document is a potential adjustment. Produce exactly what is asked and nothing more. Do not volunteer explanations or interpretations. Get counsel before you respond to the IDR.

How CDTFA Builds Its Assessment

CDTFA auditors frequently use statistical sampling to extend findings across the entire audit period. The methodology works like this: the auditor selects a sample of your transactions, calculates an error rate within that sample, and then projects that error rate across every transaction in scope. An error rate of 8 percent in the sample becomes an 8 percent error across every dollar of sales you made during the audit period. That is how a modest sample discrepancy becomes a six-figure assessment.

How Sampling Works Against You

Sampling is not neutral. It favors CDTFA when the sample is drawn from your worst periods. It favors CDTFA when the error rate in the sample does not reflect your typical business operations. It favors CDTFA when the population of transactions used for extrapolation is too broadly defined.

All of these are issues that can be challenged. Challenging the sampling methodology, including how the sample was drawn, which transactions were included, and how errors were classified, is one of the most powerful tools in CDTFA audit defense. And one of the most underused, because most business owners do not find out the methodology was flawed until after the assessment is already final.

The Sample Period Problem

CDTFA has discretion in choosing the sample period. An auditor who selects your worst quarter, a period that includes an anomalous spike in sales, or a time when your record-keeping was less organized than usual will produce a projected assessment that can be three to five times higher than what any representative period would show.

The sample period selection is one of the first and most consequential battles in any CDTFA audit. Most taxpayers do not know it is a battle at all until it is over. An experienced CDTFA audit defense attorney engages on sampling methodology from the first contact with the auditor, not after the assessment has been issued.

The Appeal Ladder: Your Rights After an Assessment

If the audit proceeds and CDTFA issues a Notice of Determination, you have rights. The appeal structure has three main levels, and each level matters.

What to Do Right Now: The 72-Hour List

This is what I tell every client who calls me after receiving a CDTFA audit notice.

• Note the exact date on the notice. Not the date you opened it. The date it was issued. That date is the beginning of every deadline.
• Do not contact the auditor yet. I understand the impulse. You want to explain yourself, correct any misunderstanding, demonstrate that you are cooperative and have nothing to hide. Wait. Once you make contact, the record starts.
• Do not produce any documents yet. Even if the IDR has arrived. Nothing leaves your hands until you have talked to counsel and determined exactly what should be produced, in what form, for what period.
• Gather your records internally. Know where your sales records, exemption certificates, purchase records, and prior returns are. Do not send them anywhere, but know exactly where they are.
• Identify your exposure. If you already suspect where the issue is, a period where records were disorganized, a product category where your taxability treatment may not be correct, an employee who left without documentation, bring that information to your attorney. Understanding your exposure before the auditor gets there is the entire game.
• Contact a California sales tax defense attorney. Not a general tax attorney. Not your income tax CPA. Someone who handles CDTFA audits specifically and has done it repeatedly. The CDTFA audit process has its own procedures, its own leverage points, and its own patterns. General competence in tax law is not the same as knowing how CDTFA auditors work, what they respond to, and where assessments are vulnerable.

The CDTFA audit notice is not the assessment. What you do before that number gets set matters more than anything that comes after it.

Frequently Asked Questions