Sales Tax for Growing Businesses: What Actually Matters

Sales Tax for Growing Businesses: What Actually Matters

Sales tax is one of the quietest ways a growing business accumulates a serious liability. Most founders ignore it until a state sends a letter, by which point the back taxes, penalties, and interest can run into six figures.

The complication is that sales tax in the United States is not a single tax. It is 45 separate state tax systems plus thousands of local jurisdictions, each with its own rates, rules, and definitions of what is taxable. For a business selling in multiple states, the compliance burden scales fast.

Here is what growing businesses actually need to know, minus the weeds.

What changed in 2018 and why it still matters

Before 2018, a business only had to collect sales tax in states where it had a physical presence — an office, warehouse, or employees. If you were shipping from California into Texas, you did not have to worry about Texas sales tax unless you had something physical in Texas.

Then the Supreme Court decided South Dakota v. Wayfair. The ruling: states can require out-of-state businesses to collect sales tax based on "economic nexus" — typically crossing a threshold of sales volume or transaction count in that state, regardless of physical presence.

Almost every state adopted economic nexus laws within 18 months of the ruling. The thresholds vary. Most states use $100,000 in sales or 200 transactions in a 12-month period as the trigger. Some states use $250,000. A few use higher or lower. Once you cross the threshold, you have to register, collect, and remit sales tax in that state going forward.

This means a CPG brand that launches DTC nationally can trigger nexus in 10 to 20 states within the first year without ever setting foot in them.

Physical nexus still matters too

Economic nexus added a layer on top of physical nexus — it did not replace it.

Physical nexus triggers are simpler. You have an office, warehouse, remote employee, inventory in a 3PL, or even a traveling sales rep in a state, and you have physical nexus there. The threshold is essentially zero. Inventory in an Amazon FBA warehouse creates nexus in whichever state the warehouse sits in — which is how Amazon sellers ended up with nexus in 20+ states simultaneously.

If you are a remote-first company with employees in 12 states, you have physical nexus in 12 states. If your 3PL has warehouses in 4 states and moves your inventory between them, you likely have physical nexus in all 4.

Physical nexus obligations apply from day one of the triggering activity. There is no safe harbor.

What is actually taxable

Not everything sold is subject to sales tax. Each state defines its own rules.

Tangible personal property is generally taxable in most states. Services are sometimes taxable, sometimes not, depending on the state and the type of service. Software as a service (SaaS) is taxable in some states and not others. Food, medicine, and clothing are often exempt or taxed at a reduced rate — and each state draws the lines differently.

The complication for CPG brands: a product that is "food" in one state (and exempt) might be a "snack" in another (and taxable). Beverage sales tax rules are particularly varied. Dietary supplements, protein bars, kombucha, and similar borderline products have been the subject of many state-level rulings.

For services businesses, this can be even murkier. A consulting firm might be tax-exempt in one state and taxable in another. A digital product might be taxable in one state based on where the customer is, and in another based on where the business is.

The rule of thumb: do not guess. For each state where you have nexus, get a clear read on whether your specific products or services are taxable. This is exactly the kind of question a sales tax specialist or a CPA with multi-state expertise can answer.

The registration and collection process

Once you determine you have nexus in a state and your products are taxable, the process is:

Register for a sales tax permit in that state. This is usually done online through the state's department of revenue and is free or low-cost.

Configure your sales platforms (Shopify, Amazon, your accounting system) to collect sales tax at the correct rate for that state. Rates vary by jurisdiction — not just state rates, but county, city, and special district rates that stack on top. Sales tax software like Avalara or TaxJar handles this automatically.

File sales tax returns on the schedule the state assigns — monthly, quarterly, or annually depending on your volume.

Remit the tax collected to the state by the due date.

The process itself is manageable with the right software. The problem is usually that businesses register late — after already having crossed nexus thresholds — and now owe back taxes on sales they made before registering.

What to do if you are already behind

If you realize you have been operating in states without collecting sales tax and you are probably past the nexus threshold, you have options.

Many states offer **voluntary disclosure agreements** (VDAs). You come forward, disclose the period you should have been collecting, pay the back taxes (and usually some interest), and the state waives or reduces penalties and limits the lookback period. VDAs are generally better than waiting for the state to find you, which results in full penalties and a longer lookback.

Some businesses use a **third-party nexus study** to review their multi-state exposure. These typically cost a few thousand dollars and produce a clear picture of where you have nexus, where you are exposed, and what VDA options make sense.

The worst option is to keep doing nothing. State departments of revenue share data with each other, cross-reference with federal tax returns, and increasingly use data from marketplaces to identify non-compliant sellers. The question is not whether you get caught, but when and how expensive it gets.

When to start paying attention

For DTC businesses shipping product nationally: start tracking sales by state from day one. Register when you cross nexus thresholds — not after you have exceeded them for a year.

For service businesses: when you hire your first remote employee in a new state, or when you start doing business in a state with a taxable service, get clarity on what you need to do.

For CPG brands selling through retailers: retailers collect sales tax on the final sale to consumers, so your wholesale sales to them are generally exempt. But DTC sales, samples, and direct-to-consumer channels follow the rules above.

For any growing business: once you are over $1M in annual revenue and operating in multiple states, a sales tax review is worth doing. A small upfront cost prevents a potentially large liability.

The conversation your CPA may not be having

Many CPAs handle federal and state income tax but do not do sales tax compliance. It is a specialty area. If your current accountant is not asking you about nexus, which states you ship to, how many transactions you process, and whether your products are taxable — it is not because you have no exposure. It is because nobody has looked.

A quick sales tax review can happen in a few hours. It is a small effort that often surfaces a significant exposure. Whether that exposure requires immediate action depends on the numbers, but you cannot make that call without having the conversation.

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*Thryve provides tax services including sales tax compliance for multi-state and e-commerce businesses. If your sales tax situation feels fuzzy, a Quick Review is a good place to start getting clarity.*