Connecticut Sales Tax Audit Guide

Connecticut sales tax audits are conducted by the Connecticut Department of Revenue Services, known as the DRS. Connecticut imposes a general sales and use tax rate and has one of the most sophisticated audit programs in New England. The DRS is particularly focused on SaaS and digital goods taxability, meals and prepared food compliance, retailer nexus thresholds, and exemption certificate enforcement. Connecticut has expanded its digital economy tax rules significantly in recent years, and technology companies, SaaS providers, and businesses that sell digital content face heightened audit risk for historical periods when they may not have been collecting tax on taxable transactions.

Statute of Limitations

Connecticut has a three-year statute of limitations for sales tax assessments, running from the date the return was due. For fraudulent returns or failure to file, the limitation period does not apply, and the DRS can assess tax for any period without time restriction. Businesses that have not been filing Connecticut returns face unlimited lookback exposure for all unfiled periods. Connecticut's DRS has an active non-filer detection program that uses business entity tax data and out-of-state business registrations to identify businesses with Connecticut sales activity that are not remitting sales tax.

How Businesses Are Selected

The DRS selects audit targets through data analytics comparing sales tax returns against business entity tax filings, payroll records, and industry norms. The Department also receives referrals from the IRS under information sharing agreements, and federal audit findings frequently trigger Connecticut examinations. The DRS conducts targeted industry sweeps, and businesses in retail, food service, construction, and technology services are regular audit targets.

Connecticut adopted economic nexus standards in 2019, requiring out-of-state sellers with more than $100,000 in Connecticut sales to register and collect tax. The DRS actively enforces these requirements and uses marketplace facilitator data and IRS records to identify non-registrants. Businesses that exceed the threshold and have not registered face significant audit exposure for unregistered periods.

High-Risk Areas in Connecticut

• SaaS and digital goods: Connecticut taxes computer and data processing services, including software as a service and cloud-based services accessed by Connecticut users. The line between taxable computer services and nontaxable professional services is frequently contested in DRS audits, and the rules have evolved through litigation and guidance.
• Meals and prepared food: Connecticut taxes meals served by restaurants, caterers, and food service establishments. The distinction between taxable prepared food and exempt grocery items is a frequent audit issue, and the DRS is aggressive in auditing food service businesses that have not consistently applied the correct treatment.
• Retailer nexus thresholds: Out-of-state retailers who cross Connecticut's economic nexus threshold but have not registered face lookback exposure. The DRS uses marketplace data and payment processor records to identify unregistered sellers.
• Construction contractors: Connecticut has specific rules governing sales tax on materials used by contractors in real property improvement versus repair work. Contractors face audit exposure when these distinctions are not applied correctly to materials and subcontract costs.
• Exemption certificate management: Connecticut sellers must maintain valid exemption certificates for all exempt sales. Missing or expired certificates create liability for the seller regardless of the actual nature of the underlying transaction.
• Manufacturing exemptions: Connecticut provides exemptions for machinery and equipment used in manufacturing and R&D. The DRS applies a direct-use test and denies exemptions for equipment used in support activities.

SaaS and Digital Products

Connecticut is one of the states that most aggressively taxes SaaS and cloud-based services as computer and data processing services. Technology companies that have characterized their subscription offerings as nontaxable professional services face significant audit exposure if the DRS determines the service is more properly classified as taxable computer processing. The legal analysis depends on the specific functionality and delivery method of the product.

Restaurant and Meals Tax Compliance

Connecticut's meals tax applies to food and beverages sold by restaurants, caterers, and food service establishments for immediate consumption. The DRS uses POS system data, supplier purchase records, and industry benchmarks to identify restaurants where reported taxable sales appear inconsistent with purchasing activity. Cash-intensive food service businesses are regular DRS audit targets.

Remote Seller Nexus

Connecticut's $100,000 economic nexus threshold applies to all out-of-state sellers making sales into Connecticut. Remote sellers who have established nexus but have not registered face lookback audit exposure for all periods since nexus was established, with no statute of limitations protection for periods when no return was filed.

The Connecticut Audit Process

A Connecticut audit begins with a written notice from the DRS identifying the audit period and requesting records. The auditor schedules an initial meeting to review the scope and establish document request timelines. DRS auditors use statistical sampling, selecting a test period, calculating an error rate, and extrapolating that rate across the full audit window. After fieldwork, the DRS issues a Notice of Assessment setting out the proposed assessment and the basis for the adjustments.

After receiving a Notice of Assessment, businesses should evaluate whether to request a Taxpayer Conference with the DRS. The conference is an informal settlement opportunity within the Department. If the conference does not produce a resolution, businesses must file a timely appeal to preserve their rights to further review.

Connecticut Appeals Process

After an unfavorable DRS determination, businesses can appeal to the Connecticut Tax Session of the Superior Court. The Tax Session is a specialized division of the Superior Court with jurisdiction over state tax appeals. Tax Session proceedings involve formal discovery, evidentiary hearings, and legal briefing. The court provides independent review and is not bound by DRS positions or informal guidance.

After a Tax Session decision, appeals go to the Connecticut Appellate Court and, if necessary, to the Connecticut Supreme Court. Most Connecticut sales tax disputes are resolved at the DRS conference or Tax Session level without reaching full appellate review.

What We Look For in Connecticut Audits

• SaaS and digital service characterization: Whether a subscription product is a taxable computer service or a nontaxable professional service is a legal question that requires analysis of the specific product and how it is delivered and used.
• Sampling methodology: DRS auditors must follow specific statistical procedures. Challenges to the test period and extrapolation methodology frequently reduce assessments significantly.
• Meals tax classification: The line between taxable prepared food and exempt grocery items requires careful review of product-level sales data and how items are marketed and sold.
• Exemption certificate cure: Connecticut allows sellers to obtain replacement certificates after an audit notice for transactions that were genuine exempt sales.
• Penalty abatement: Connecticut allows penalty waiver for reasonable cause, first-time audit findings, and good-faith reliance on professional advice.