What to Expect in a California CDTFA Sales Tax Audit

Marc Boulanger • June 20, 2025

How to Prepare, Respond, and Protect Your Business

A desk with papers and a laptop and the words navigating your california cdtfa audit

If you’re facing a sales tax audit from the California Department of Tax and Fee Administration (CDTFA), you’re not alone — and you’re right to take it seriously. These audits are notoriously aggressive, time-consuming, and can result in tens or even hundreds of thousands of dollars in assessed liability.


At Boulanger CPA and Consulting PC, we specialize in helping California business owners navigate CDTFA audits strategically — not just compliantly. In this guide, we’ll walk you through exactly what to expect, why the CDTFA audits small businesses so aggressively, and how to protect yourself from common pitfalls.


What Triggers a CDTFA Audit?


The CDTFA doesn’t randomly audit businesses. They audit when they see red flags — and some of the most common triggers include:


  • High cash transactions (e.g., restaurants, vape shops, liquor stores)
  • Inconsistent sales tax reporting vs. income tax returns
  • Late or missing sales tax returns
  • Prior audits (especially if they found issues)
  • Industry-specific audit targets
  • Tips from former employees or competitors


Pro Tip: The CDTFA compares your sales tax filings with other agencies — including the IRS, FTB, and EDD. Inconsistencies across agencies almost always lead to deeper investigations. If you're already facing an FTB audit or collections issue, it’s especially important to coordinate your records and strategy.


What to Expect in a CDTFA Audit


Here’s how a typical audit unfolds:


Step 1: Initial Contact


The CDTFA will send you a Notification of Audit via mail. This includes:


  • The audit period (usually 3 years)
  • The name of the auditor
  • A request for books, records, and access to your POS system


Step 2: Information Request


You’ll be asked to provide:


  • Sales tax returns
  • Federal and state income tax returns
  • Bank statements
  • Purchase invoices
  • Sales journals
  • Daily sales summaries or Z-tapes
  • POS system reports
  • 1099-Ks if you use Square, Stripe, or similar
What to Expect in a CDTFA Audit includes deep data mining. The auditor is trained to assume you may be underreporting unless proven otherwise.

Step 3: Initial Interview


The auditor will typically conduct a phone or in-person interview where they ask:


  • About your business operations
  • Sales methods (cash, card, online, etc.)
  • Inventory or markup procedures
  • Industry-specific questions (especially in food, alcohol, or auto)
🎯 Tip: Every word you say in this interview can impact your outcome. Do not go in without professional representation.

Step 4: Testing + Estimation Methods


If your records are incomplete or inconsistent, the CDTFA will use estimation techniques like:


  • Markup testing
  • Extrapolation from sample months
  • Bank deposit analysis
  • Third-party data comparisons (e.g., delivery platforms, wholesalers)


What to Expect If You Have Incomplete Records


Missing records or inaccurate reports = danger zone. The CDTFA is legally allowed to estimate your sales — and they always estimate high.


Common audit adjustments include:


  • “Estimated underreported sales” based on industry averages
  • “Unverified cash sales” added to reported totals
  • “Uncaptured POS revenue” from Square, Clover, or Toast


This can result in:


  • Six-figure assessments
  • Penalties up to 25%
  • Interest charges
  • Referral to the Franchise Tax Board (FTB) for income tax mismatches
  • Referrals to EDD for employment tax audits
  • In rare cases, criminal investigation


Can You Settle CDTFA Audit Debt?


Yes — but the rules are different from the IRS. You may be eligible for:


  • Managed audit programs (reduces penalties)
  • Settlement through Offer in Compromise (rare for active businesses but possible for closed/insolvent businesses)
  • Appeal and protest through the Office of Tax Appeals (OTA)
  • Payment plans (Installment Agreements)


The key is: you must respond early and strategically. Once a Notice of Determination is issued, the window to fight it closes fast. For full representation, explore our California sales tax audit defense solutions.


CDTFA vs IRS: Which Is Worse?

Many business owners assume the IRS is their biggest threat — until they meet the CDTFA.

Category CDTFA IRS
Focus Sales Tax Income + Payroll Tax
Audit Triggers Industry-based, POS data Broad-based
Record Demands Very aggressive Moderate
Estimations Frequent and severe More predictable
Settlement Options Fewer Broader (OIC, CNC)
CDTFA audits are often faster, less flexible, and more punitive than IRS audits — especially for small businesses.

Sales Suppression Audits in California — What You Need to Know


A growing number of CDTFA audits involve “sales suppression” allegations — i.e., accusations that you used:


  • Phantomware or zapper devices
  • Skimming or off-the-books systems
  • Manipulated POS reports


If flagged, these audits may include:


  • Expanded lookback periods
  • Penalty stacking
  • Referral for criminal prosecution


If you’re worried this applies to you, do not respond alone.


How to Protect Yourself During a CDTFA Audit

Get professional representation early
Do not volunteer documents or explanations without review
Don’t assume the auditor is neutral — they’re not
Keep everything in writing
Push back on estimation techniques if they’re flawed


Why Work With Us


At Boulanger CPA and Consulting PC, we:


  • Represent California businesses in CDTFA, FTB, and EDD audits
  • Use our CPA credentials and tax law knowledge to defend clients
  • Have resolved audits for restaurants, retailers, vape shops, beauty salons, and more
  • Help businesses reduce assessments, penalties, and stress


Get CDTFA Audit Help Now


If you’ve received a CDTFA audit notice, don’t wait. We’ll walk you through the process, protect your records, and fight for a fair outcome.


Based in Orange County. Serving all of California. Virtual consults available statewide.


👉  Schedule your free audit strategy call now

  • What is a CDTFA audit?

    A CDTFA audit is a review of your sales tax records to verify correct tax reporting. It typically covers 3 years and focuses on sales totals, tax collected, and documentation.

  • How long does a CDTFA audit take?

    Most audits take 3 to 6 months, depending on complexity, business type, and record completeness.

  • What if I disagree with the auditor?

    You can appeal through the CDTFA’s appeals process or the Office of Tax Appeals (OTA). You should work with a qualified representative before this stage.

  • Will the CDTFA notify other agencies?

    Yes — the CDTFA commonly shares audit results with the FTB, EDD, and sometimes the IRS if income or payroll tax discrepancies are found.


📣 About the Author


Marc Boulanger, CPA
 is the founder of Boulanger CPA and Consulting PC, a boutique tax resolution firm based in Orange County, California and trusted by high-income individuals and business owners across Southern California.


He is the author of Defend What’s Yours: A California Taxpayer’s Guide to Beating the IRS and FTB at Their Own Game, available now on Amazon. The book offers a step-by-step plan for resolving IRS and FTB tax debt without losing your business, your home, or your peace of mind.


With over a decade of experience resolving high-stakes IRS and State tax matters, Marc brings strategic insight to complex cases involving wage garnishments, bank levies, unfiled returns, and six-figure tax debts. He is known for helping clients reduce or eliminate tax liabilities through expertly negotiated settlements and compliance plans.


Marc is a Certified Public Accountant licensed in California and Oklahoma and holds the designation of Certified Tax Representation Consultant. He is a member of the American Society of Tax Problem Solvers (ASTPS) — the national organization founded by the educators and practitioners who have trained thousands of CPAs, EAs, and tax attorneys in IRS representation strategy.


Every case is handled with discretion, proven methodology, and direct CPA-led representation — not call center scripts.


📍 Learn more at www.orangecounty.cpa or call (657) 218-5700.


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