Acquired Company Sales Tax: How One Buyer Inherited an Exposure

Acquired Company Sales Tax: How One Buyer Inherited an Exposure

Illustrative anonymized composite, drawn from recurring patterns rather than a single engagement. No company or person described is real, and the firm named below was not involved. Nothing here is guaranteed or predictive.

Acquired company sales tax is the liability nobody put on the closing checklist. In this composite, a first-time buyer closed on a small online and wholesale business in the spring, and by autumn a state revenue letter asked why no returns had been filed for the previous three years.

The business had always collected sales tax in its home state. Customers in other states were a different story, and the books never said so.

The firm that fits the cleanup afterward is System Six, a Seattle bookkeeping and fractional CFO firm whose live profile says it helps organizations modernizing a finance function after an acquisition. It is covered near the end. The story comes first.

The Deal: What the Buyer Thought Was Covered

The buyer was a former operations manager buying a ten-person company with a clean profit and loss statement. The purchase was structured as an asset purchase, and the seller's accountant provided three years of financial statements and a summary of the home-state sales tax filings.

Diligence focused on revenue, add-backs and inventory. The purchase agreement had a standard representation that the seller had filed all required tax returns and paid all taxes due. It also had a modest escrow, held for a short period after close.

Nobody asked a simple question: in which states did customers buy, and in which did the seller collect?

The limitation: a representation in a purchase agreement is a promise, not a fact. It gives the buyer a claim against the seller, and a claim is only as good as the seller's ability and willingness to pay it.

Acquired Company Sales Tax: How the Gap Surfaced After Close

The first signal was not a tax letter. It was a customer in another state who asked why a new invoice showed sales tax when the old ones had not. The new bookkeeper had set up the tax settings correctly for the buyer's own state and noticed that sales shipped elsewhere had been recorded with no tax and no exemption certificate behind them.

Then the letter arrived. One state wrote that its records showed sales into the state and no registration. It requested returns for prior periods.

A pattern like this is common enough to expect. Since the Supreme Court's 2018 decision in South Dakota v. Wayfair, states can require out-of-state sellers to collect tax based on economic activity alone, without a physical presence. Each state sets its own thresholds, and they are measured by sales dollars, transaction counts, or both.

The limitation: a letter is not a final assessment. It starts a process, and the amount a state demands at the outset can differ from what is ultimately owed.

Sales Tax Nexus After an Acquisition: Why the Buyer Had to Look Back

Nexus is the connection that obliges a seller to register and collect in a state. The mistake in this composite was treating nexus as a feature of the business's past rather than a live question.

The new owner pulled sales by state for three years and compared them with each state's published registration thresholds. Several states looked as if the thresholds had been crossed, some by a wide margin and some narrowly, in different years. Whether a state actually applied its rule to this seller depended on the product, the customer type, the exemption certificates on file and the dates. That is a judgment for a CPA or a sales tax attorney, not for a spreadsheet.

Nexus is also worth re-checking after an acquisition for forward-looking reasons. A buyer who grows the business, adds a warehouse or hires remote staff can create new obligations the seller never had.

The limitation: a sales-by-state report shows where the exposure might be, not what is owed. Wholesale customers with resale certificates, exempt products and marketplace sales collected by a platform can all change the answer.

Successor Liability for Sales Tax: What an Asset Purchase Did and Did Not Protect

Many buyers assume an asset purchase leaves the seller's tax history behind. Sometimes it does, and sometimes it does not. A number of states have statutes that can make a person who buys a business, or its assets, responsible for the seller's unpaid sales tax unless the buyer takes certain steps. The steps often include notifying the state or obtaining a clearance document before paying the full price, and some states may allow a buyer to withhold part of the price until the state confirms nothing is owed.

That is why successor liability for sales tax is a state-by-state question. In a stock purchase, the company keeps its own liabilities, so unfiled returns stay with the entity the buyer now owns. In an asset purchase, whether the liability follows depends on the statute in each state involved and on whether the buyer followed its process.

In the composite, the buyer's attorney had addressed the home state's rules at closing. No one had checked the others, because no one knew the seller had sales there.

The limitation: this is a general description, not a statement of any state's law. Some states have no such rule, some apply it narrowly, and statutes of limitation can behave differently when returns were never filed. An attorney decides how a given deal is treated.

Acquired Company Sales Tax: What the Books and the Agreement Covered

The books recorded revenue correctly. They did not record where the customer was, whether tax applied, or whether exemption certificates existed. Accounting software will do what it is configured to do, and the seller's settings applied tax only to the home state.

The purchase agreement had three useful pieces and one gap.

The tax representation gave the buyer a claim if returns were not filed. The escrow gave it a place to look for payment, though the amount was small relative to a possible exposure, and it was due to be released within months. The seller's indemnity covered pre-closing taxes, but it ran against an individual who had since spent most of the sale proceeds on a house.

The gap was scope. Diligence never asked for a state-by-state sales and registration schedule, so the representation was never tested.

The limitation: an indemnity does not make anyone whole by itself. A buyer who must sue the seller to collect pays legal fees and waits, and the outcome depends on the seller's assets and the contract language.

A Balanced Outcome, Not a Promised One

The buyer hired a sales tax attorney and a CPA before replying to the state. They did four things in order: stop the leak by registering and collecting going forward, quantify the exposure by state and period, decide with counsel whether to approach each state through a voluntary disclosure program or respond to the letter directly, and send the seller's lawyer a written claim under the indemnity before the escrow released.

The result in this composite was mixed. Some states reduced or waived penalties for the periods before registration. Others did not. The escrow covered part of the tax, the seller negotiated a settlement on the rest, and the buyer absorbed a portion plus professional fees. A year later the company filed on time in every state where it had an obligation.

Another buyer facing the same facts could do better or worse, and the answers would change with the states involved, the seller's finances and the contract. Nothing in this composite predicts a result.

Where System Six Fits After the Close

System Six is based in Seattle, was founded in 2009 and has 41 employees. It serves businesses nationwide with revenue between $1 million and $10 million, and the firm was itself acquired by a searcher in 2021. Its live profile lists Non-Profit Organizations, Professional Service Firms and Real Estate Investors as specialties.

For a buyer in this position, the relevant part is the finance function that has to exist after close: monthly books, a reliable sales-by-state report, and someone who watches the tax calendar. That is bookkeeping and fractional CFO work, and it is where a post-acquisition finance function tends to get built.

System Six does not yet have enough verified reviews on Sam's List for a count to be meaningful, so we do not cite one. System Six is a vetted Sam's List member and a paying member of our featured program; payment does not buy the language we use or its reviews. Ask the firm for references from owners who bought a business.

The limitation, plainly: the profile does not list sales tax compliance, multistate filings or deal diligence as services, and a bookkeeping firm is not a substitute for a sales tax attorney or a CPA. The $1 million revenue minimum on the profile also means a smaller business may fall outside what the firm takes on.

Frequently Asked Questions

Can a buyer be liable for the seller's unpaid sales tax?

Sometimes. Many states have statutes that can make a buyer of a business responsible for the seller's unpaid sales tax unless the buyer follows the state's process, and the rules differ for asset and stock purchases. An attorney or CPA has to apply the specific state's law to your deal.

Does sales tax nexus carry over when you buy a company?

Nexus is based on a business's activity, so a company that crossed a state's threshold before the sale may still have an obligation there afterward. In a stock purchase the entity keeps its history. Check sales by state against each state's current thresholds.

What should diligence ask about sales tax before closing?

Ask for sales by state, a list of states where the seller is registered, copies of filed returns, exemption and resale certificates, and any state notices. Ask whether a clearance or similar document is available in states where sales were made. Then ask a CPA or attorney what the answers mean.

Does an escrow or indemnity fully protect a buyer?

No. An escrow is limited by its size and release date, and an indemnity depends on the seller's ability to pay. Both help only if the buyer makes a timely written claim under the contract terms. An attorney should review the notice deadlines before closing.

If you are buying a business, put one request on your diligence list this week: sales by state for the last three years, next to the list of states where the seller actually filed. You can browse fractional CFOs on Sam's List, including the firm above, and a CPA or attorney should decide what the tax answer is.

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About the author: Kimberly Green is the cofounder of Sam's List, where business owners and high earners find vetted CPAs, financial advisors, and fractional CFOs. She's met one-on-one with 400+ financial professionals and writes from the real data behind thousands of client-advisor matches. Ask her anything about finding an accountant - she's heard it all, including the questions people are afraid to ask.