How to Handle Back Taxes When You’ve Been Operating in a State Without Registering

The scenario is more common than most founders want to admit. Your business has been selling products or services in multiple states for a year or two, maybe longer, and you just discovered you were supposed to be registered for sales tax or income tax in some of those states. Nobody flagged it. Your bookkeeper did not catch it. You were busy building the business. 

Now what? 

This is not a rare situation. In fact, since the Supreme Court’s 2018 ruling in South Dakota v. Wayfair, Inc., the rules around state tax obligations changed significantly for businesses of all sizes. Before Wayfair, a company generally needed a physical presence in a state (like an office or warehouse) before that state could require it to collect and remit sales tax. After Wayfair, states can impose sales tax collection obligations based on economic activity alone. 

Today, more than 45 states and the District of Columbia impose a sales tax, and most of them have established economic nexus thresholds, typically $100,000 in annual sales or 200 separate transactions within the state. If your business has crossed those thresholds and has not registered, it has likely been accumulating an unregistered tax liability with every passing month. 

Here is the good news: there are clear, structured paths to address this, and handling it proactively is almost always better than waiting for a state to find you first. 

Understanding What You Actually Owe 

The first step is getting a clear picture of your exposure. That means conducting a nexus study, which is a review of where your business has customers, employees, contractors, inventory, or any other taxable connections. A proper nexus study will identify which states you should have been registered in, how long that obligation likely existed, and what types of taxes are involved, whether sales tax, income tax, franchise tax, or a combination. 

Once you understand the scope, you can evaluate your options. The two most common paths are retroactive voluntary registration through a state’s own program or participation in a formal Voluntary Disclosure Agreement, commonly referred to as a VDA. 

Voluntary disclosure is generally the preferred approach when you want penalty protection and a limited lookback period. Most states participating in VDA programs offer a lookback window of three to four years, compared to the full statute of limitations period (often five or more years) that applies in a state-initiated audit. But even for businesses that do not qualify for or choose not to pursue a VDA, retroactive registration and filing back returns can still reduce long-term exposure compared to doing nothing at all. 

What Happens If You Do Nothing 

Some business owners weigh the risk and decide to wait it out, hoping a state never audits them. This is a costly gamble. States are increasingly sophisticated in identifying non-filers through third-party data, marketplace transaction records, and cross-referencing federal business registrations. When a state finds you before you come forward, the consequences are almost always worse. 

Once a state initiates contact or opens an audit, you lose access to penalty waiver programs. Interest continues to accumulate. And the audit process itself can be disruptive to operations, pulling your team away from running the business to locate records and respond to requests. 

According to the Tax Foundation, state tax enforcement activities have increased substantially since the Wayfair decision, as states have invested in data analytics capabilities specifically designed to identify non-compliant remote sellers. A state tax authority can now more easily connect the dots between your federal filing activity, payment processor data, and in-state customer records. Proactive disclosure is not just ethically sound. It is strategically smart. 

A Step-by-Step Path Forward 

If you have discovered a gap in your state tax compliance, here is how to approach it. 

Start with a nexus study. Work with a qualified tax professional to identify every state where you may have an obligation. Do not guess. A proper review looks at your sales data, employee locations, contractor relationships, and any physical assets tied to states where you operate. 

Quantify the liability. For each state where you have exposure, estimate the back taxes owed. This typically requires pulling historical sales records and applying that state’s tax rates and rules to your transactions. Some states have special provisions for specific industries or product types, so this analysis requires real attention to detail and cannot be done accurately without good historical data. 

Evaluate your disclosure options. Some states have their own voluntary disclosure programs. Others participate in the Multistate Tax Commission’s National Nexus Program, which allows businesses to simultaneously pursue disclosure in multiple states through a single application. Your tax advisor can help determine the most efficient path given the states involved and the scope of your exposure. 

Gather and organize your documentation. Back filings require clean records. If your books are not in order, you will need to reconstruct transaction history before you can file accurately. This is where having strong financial operations infrastructure pays off. Businesses that work with Escalon’s financial operations team tend to maintain cleaner historical records, which makes retroactive compliance significantly easier and less expensive. 

File and pay. Once your filings are prepared, submit them with any payments owed. If cash flow is a concern, some states allow installment arrangements for back tax liabilities. 

Set up proper compliance going forward. Registering in new states, filing regularly, and keeping up with changing nexus rules is an ongoing responsibility. Sales tax automation platforms can help businesses with high transaction volumes manage multi-state compliance without adding significant administrative overhead. 

The Real Cost of Waiting 

It is worth understanding concretely what delayed action costs. State penalties for sales tax non-compliance typically range from 10 to 25 percent of unpaid tax, on top of interest that accrues from the original due date. For a business with $500,000 in taxable sales across multiple states over three years, the penalty and interest exposure can easily reach tens of thousands of dollars, in addition to the underlying tax itself. 

Contrast that with a voluntary disclosure outcome where penalties are typically waived entirely and the lookback period is limited to three years or fewer. The financial case for proactive action is almost always compelling when you run the actual numbers. 

The Importance of Experienced Guidance 

State tax law is not uniform. Every state has different rules around what triggers nexus, what transactions are taxable, what rates apply, and how penalties are assessed. A business selling physical goods faces different considerations than a SaaS company or a professional services firm. Getting this wrong, even with good intentions, can create new problems. 

This is particularly true when reconstructing historical liability. Applying the wrong tax rates, missing product-level exemptions, or incorrectly calculating the start date of your nexus can result in overpaying or underpaying, both of which create their own complications. 

Working with tax professionals who have multi-state experience is not optional when you are cleaning up a compliance backlog. Escalon’s tax operations team works with startups and growing businesses to conduct nexus studies, manage voluntary disclosure filings, and establish ongoing state tax compliance programs that scale with the business. 

You are not the first founder to find yourself in this situation. And you do not have to navigate it alone. 

Ready to Get Compliant? 

Whether you are just beginning to understand your exposure or you already know you have a multi-state tax problem that needs to be resolved, the most important move is to take action now rather than later. The longer the liability sits unaddressed, the more it grows and the fewer favorable options remain available to you. 

Contact Escalon today  to speak with a tax professional who can walk you through your options, help you quantify your exposure, and build a plan to get your business into compliance on the best possible terms.