CDTFA Sales Suppression Audits Explained – What California Business Owners Need to Know

Marc Boulanger • June 24, 2025

If you operate a cash-heavy or point-of-sale–dependent business in California, there’s a specific type of audit that can hit you hard—fast—and with serious criminal overtones: the CDTFA Sales Suppression Audit.


These audits go far beyond simple record reviews. They’re aimed at catching businesses that intentionally underreport sales through digital manipulation or hidden technology—often without even knowing they’re doing something illegal.



At Boulanger CPA and Consulting PC, we defend California business owners facing complex CDTFA audits and potential fraud accusations. If you've received an audit notice related to sales suppression—or want to avoid one—this guide is for you.


What Is Sales Suppression?

Sales suppression is the intentional or accidental underreporting of sales—often cash sales—by manipulating your point-of-sale (POS) system, deleting transaction records, or using “zapper” software to skim data before reporting.


Common examples include:


  • Deleting sales from the POS system

  • Using dual sets of books (one for reporting, one for internal use)

  • Adjusting Z-tape totals before submitting to the CDTFA

  • Using software that modifies or hides real sales numbers

  • Skimming cash sales before they hit your books

Even if you didn’t install the suppression software yourself, you may still be held liable.


What Triggers a Sales Suppression Audit?

Sales suppression audits are often triggered by:



  • Discrepancies between POS reports and sales tax returns

  • Cash-heavy business models with inconsistent deposits

  • Anonymous tips (from ex-employees, competitors, or customers)

  • Unusual ratios in audit sampling (e.g., food costs to sales in restaurants)

  • High refund or void activity in your POS data

  • Audit patterns from prior CDTFA reviews or BOE audits

  • Out-of-state equipment purchases not reported properly

Once the CDTFA suspects suppression, the case is escalated—and auditors are instructed to assume fraud until proven otherwise.

What Happens During a CDTFA Sales Suppression Audit?

Expect a highly detailed and invasive audit process, including:

1. Technology Review


Auditors may request access to:


  • POS hardware and software

  • Z-tapes and end-of-day summaries

  • Internal sales journals

  • Merchant service statements

  • Any devices used to track customer orders (e.g., tablets, mobile registers)

2. Forensic Sales Testing


The CDTFA uses industry benchmarks to estimate what your sales should have been. If actual reported sales fall outside this range, they’ll perform a markup or ratio analysis to estimate underreported tax.


3. Bank Statement Reconciliation


Auditors compare your deposits to reported gross receipts. If there are unexplained cash gaps, they’ll assume sales were suppressed.


4. Evidence Gathering


They may issue subpoenas, contact vendors, or even visit your location to observe operations.


What Are the Penalties for Sales Suppression?

Penalties can be severe—and in some cases, criminal.



  • 100% fraud penalties on unpaid tax

  • Referral to the California Attorney General for criminal prosecution

  • Permanent sales tax permit revocation

  • Personal liability for owners or corporate officers

  • Back tax assessments for 3–8 years

  • Interest and fines that exceed the original tax owed

If the CDTFA deems that sales were intentionally suppressed, it’s no longer a normal audit—it’s a potential criminal tax fraud case.


Real-World Example

A restaurant owner in Los Angeles was audited after an anonymous tip claimed they were “skimming” cash. The CDTFA discovered their POS system had a hidden export feature that omitted certain transactions. The business faced $284,000 in assessed tax, interest, and penalties. We were brought in post-audit and successfully negotiated a reduction in penalties and a manageable payment plan—but it could’ve been avoided with proper documentation and representation from the start.

How to Defend Against a Sales Suppression Audit

If you've received a CDTFA audit notice—or suspect one is coming—here’s what we recommend:


1. Hire Representation Immediately


Sales suppression cases are not DIY audits. You need someone who understands CDTFA procedure and sales tax defense.


2. Lock Down Your Records


Secure copies of all sales reports, POS data, Z-tapes, merchant statements, and tax returns.


3. Don't Talk to Auditors Alone


Even casual statements can be used to support a fraud theory. Let your CPA or attorney handle communications.


4. Prepare a Legitimate Reconciliation


If discrepancies exist, they may be explainable through timing differences, returns, theft, or system errors.


5. Correct Problems Before the Audit



If you're using outdated or questionable POS software, now is the time to fix it. Switch to a reputable provider, ensure secure reporting, and archive your sales data correctly.


Proactive Tips to Avoid Sales Suppression Allegations

  • Use cloud-based POS systems with tamper-proof audit trails

  • Retain all Z-tape reports and end-of-day summaries

  • Back up sales data externally and securely

  • Conduct periodic internal reconciliations between reported sales and deposits

  • Provide formal training for staff on cash handling and refund procedures

  • Limit manager-level overrides and voids in your POS settings

We Defend Business Owners Statewide

Boulanger CPA and Consulting PC represents business owners across California—especially in industries most likely to be targeted:


  • Restaurants and food trucks

  • Grocery and liquor stores

  • Vape and tobacco shops

  • Nail salons and barber shops

  • Car washes and detailers

  • Cannabis retailers

  • Any cash-heavy or POS-driven business

Don’t Let a Software Setting Turn Into a Six-Figure Problem

Sales suppression allegations can destroy your business and your reputation. If you've been contacted by the CDTFA—or suspect your sales records might trigger scrutiny—get ahead of it.


📞 Call (657) 218-5700 or Schedule a Confidential Audit Consultation



FAQ – CDTFA Sales Suppression Audits

  • What is a sales suppression audit?

    It’s a forensic CDTFA audit focused on identifying hidden or deleted sales from your records—usually tied to POS system manipulation.


  • Is using “zapper” software illegal in California?

    Yes. The use or possession of software that deletes or modifies sales data to reduce tax is illegal and may result in criminal charges.


  • Can I be penalized even if I didn’t know sales were being suppressed?

    Yes. CDTFA can hold you liable based on negligence or poor oversight, especially if you're the business owner or responsible party.


  • How far back can CDTFA look?

    Typically 3 years, but up to 8 years in fraud cases.

  • What industries are most at risk?

    Restaurants, salons, vape shops, cannabis dispensaries, and any high-volume cash businesses.

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📣 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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