CDTFA Representation: California Sales and Use Tax Audits and Appeals

The California Department of Tax and Fee Administration administers sales and use tax and dozens of special taxes and fees. It took over the tax programs formerly run by the State Board of Equalization, and it is the agency most likely to examine a California business that sells anything tangible.

CDTFA audits differ from income tax audits in a way that catches owners off guard: the agency is not primarily checking your arithmetic. It is testing whether your reported taxable sales are plausible given everything else it can observe about your business — your purchases, your bank deposits, your credit card ratios, your markup, and in some cases a few days of watching your register. When reported sales fail that test, the auditor estimates what sales should have been and assesses tax on the difference.

We represent businesses in CDTFA examinations, petitions, and appeals across Temecula, Murrieta, San Diego, Riverside, San Bernardino, and Orange County.

What Triggers a CDTFA Audit

Selection is partly industry-driven and partly data-driven. Common triggers include:

• A mismatch between sales reported to CDTFA and gross receipts reported on the income tax return filed with the Franchise Tax Board
• Reported taxable sales that are low relative to Form 1099-K card settlements
• Large or frequent exempt and resale sales claimed without complete certificates
• Industry membership — cash-intensive and high-audit sectors are examined on cycle
• Purchase of an existing business, which can trigger successor liability review
• Consumer or competitor complaints, and information developed in another taxpayer’s audit

In Southern California, the recurring audit populations are restaurants and bars, auto repair shops and used car dealers, construction contractors, gas stations and convenience stores, liquor and smoke shops, cannabis retailers, and increasingly e-commerce sellers with marketplace and drop-ship arrangements.

How CDTFA Auditors Build an Assessment

Because small businesses rarely have perfect records, auditors rely on indirect methods. Understanding which one is being used is the whole game, because each has known weaknesses.

Markup Analysis

The auditor determines the cost of taxable merchandise purchased, applies an assumed markup percentage, and projects what taxable sales should have been. Disputes turn on whether the markup is right — actual pricing, discounting, happy hour and promotional pricing, spoilage, breakage, employee meals, theft, and comped items all reduce realized markup and are routinely omitted from the auditor’s first computation.

Observation Tests

An auditor observes sales for a short period — sometimes a single day or a few hours — and projects that volume across the audit period. These are among the most challengeable methods available, because the observed period is rarely representative. A Tuesday in February is not a Saturday in July, and a restaurant observed during a slow month can be assessed as though every month looked like that one.

Bank Deposit and Credit Card Ratio Analysis

Deposits are treated as sales unless shown otherwise. Loan proceeds, owner capital contributions, transfers between accounts, insurance proceeds, and sales of equipment all inflate deposits without being taxable sales, and each must be traced and documented. Card-ratio methods assume a fixed cash-to-card mix and are vulnerable when the real mix shifted — which it did substantially for most retailers over the last several years.

Resale Certificates and Use Tax

Two more issues appear in nearly every audit. Sales claimed as exempt for resale require valid, timely certificates taken in good faith; incomplete or after-the-fact certificates get disallowed and the tax falls on the seller. And use tax is assessed on out-of-state purchases and on inventory withdrawn for business or personal use — a line item most businesses never self-report.

The Notice of Determination and the 30-Day Petition

When the audit concludes, CDTFA issues a Notice of Determination — the billing that starts the appeal clock.

You have 30 days to file a Petition for Redetermination. This deadline is materially shorter than the 60 days California gives you to protest an FTB assessment, and it is the deadline most often missed. Per CDTFA guidance, if the petition is not filed within 30 days, the determination becomes final, due, and payable. Collection follows, and the only remaining route is to pay the liability in full and file a claim for refund.

A petition should identify each disputed item, state the legal and factual basis, and preserve every issue you may later want to argue. Issues left out are difficult to add back in.

Appeals Bureau and the Office of Tax Appeals

A timely petition routes the case to the CDTFA Appeals Bureau, which is separate from the audit function. An appeals conference is scheduled — typically informal, with the taxpayer or representative presenting evidence and argument — and the Bureau issues a written Decision and Recommendation.

If that decision is unfavorable, the appeal goes to the Office of Tax Appeals, generally within 30 days. OTA hears the matter before a panel of three Administrative Law Judges independent of CDTFA, and publishes precedential opinions.

Most CDTFA cases that resolve favorably resolve on the numbers rather than on a legal principle — a markup percentage corrected, a test period shown to be unrepresentative, deposits traced to non-sale sources. That work belongs in the audit and the Appeals Bureau conference, where the record is still being made.

Personal and Successor Liability

Two exposures make sales tax different from other business taxes, and both routinely surprise clients.

Responsible person liability. Under Revenue and Taxation Code section 6829, when a corporation or LLC terminates or becomes insolvent, CDTFA can assess unpaid sales tax personally against officers, members, managers, or other responsible persons who had control over filing and paying and who willfully failed to do so. Dissolving the entity does not extinguish the debt — it can redirect it to you. This mirrors federal trust fund recovery penalty exposure, which we address in our business tax audit practice.

Successor liability. A buyer who purchases a business or its stock of goods can be liable for the seller’s unpaid sales tax up to the purchase price, unless a certificate of tax clearance is obtained before closing. This is a routine and avoidable diligence item, and it is missed constantly. If you are buying or selling a business, the clearance certificate belongs on the closing checklist.

Resolution and Relief

Where the liability is correct but unpayable, CDTFA offers installment payment agreements and its own offer in compromise program. Individuals who owe multiple California agencies can apply to FTB, CDTFA, and EDD together using the multi-agency form DE 999CA; entities file separately on CDTFA 490-C and FTB 4905 BE. Each agency evaluates independently — approval by one does not bind another. Our offer in compromise page covers both the federal and California programs.

Penalty relief is available for reasonable cause, and the negligence penalty in particular is often reduced or removed where the taxpayer’s records were maintained in good faith and the deficiency arose from a technical misunderstanding rather than disregard.

Frequently Asked Questions

How long do I have to appeal a CDTFA Notice of Determination?

30 days from the date of the notice to file a Petition for Redetermination. Missing that deadline makes the liability final, due, and payable, leaving only pay-and-claim-refund.

Can CDTFA estimate my sales if my records are incomplete?

Yes. Where records are inadequate, the auditor may use indirect methods — markup analysis, observation tests, bank deposit analysis, or credit card ratios. The estimate is rebuttable, but the burden of showing it is wrong falls on the taxpayer.

Am I personally liable for my company’s unpaid sales tax?

You can be. Under R&TC 6829, responsible persons who willfully failed to pay can be assessed personally when the entity terminates or becomes insolvent. Closing the business does not end the exposure.

What happens if a customer’s resale certificate turns out to be invalid?

The tax generally falls on the seller. Certificates must be valid, complete, and taken in good faith at the time of sale; certificates gathered after an audit begins are frequently disallowed.

Is a CDTFA audit the same as an FTB or IRS audit?

No. Different agency, different tax, different deadlines, and a different first appellate step. Businesses are sometimes examined by more than one agency at once, and the clocks run independently.

Can I be audited for periods where I already have a payment plan?

Yes. An installment agreement resolves how an existing liability is paid; it does not close the underlying periods to examination.

Get Representation Before the Deadline Runs

The two moments that decide most CDTFA cases are the audit itself — where the method is chosen and the record is built — and the 30 days after the Notice of Determination. Both are short, and both are recoverable only while they are still open.

Pietro Canestrelli holds an LL.M. in Taxation and represents California businesses before CDTFA, the FTB, the EDD, the Office of Tax Appeals, and the IRS. Schedule a consultation, or learn more about our business law and corporate tax services.