Most buyers spend real energy vetting the business itself: revenue trends, customer concentration, equipment condition.
What gets far less scrutiny is the quality of the tax work sitting behind the financials, and that gap can turn into a six-figure problem after close.
Seller-side tax mistakes do not disappear when buying a business. In plenty of cases they follow the business and become the buyer’s problem.
Knowing where that risk hides is one of the more underrated skills in acquisition due diligence, so we want to walk through where we actually find it.
Seller Tax Mistakes Often Survive the Ownership Transfer
When you buy a business’s assets, you generally get a clean break from the seller’s prior tax liabilities. That is one of the main reasons buyers prefer asset purchases to stock purchases.
The clean break is not always complete, though.
Payroll tax issues, sales tax obligations, and certain employment-related liabilities can follow the business even in an asset deal, depending on how the transaction is structured and which state you are operating in.
Stock purchases carry substantially more risk. When you acquire the legal entity itself, you step into all of it: open tax years, unfiled returns, misclassified workers, and any notices that were quietly filed away rather than answered.
Which brings us to the question buyers should be asking before they pick a structure.
How Far Back Can Any of This Reach?
Further than most buyers assume, and the answer is written into the statute rather than left to IRS discretion.
Under 26 U.S.C. section 6501, tax is generally assessed within three years of the return being filed. That window stretches to six years where the taxpayer omitted gross income “in excess of 25 percent of the amount of gross income stated in the return”. And for a false or fraudulent return filed with intent to evade tax, the statute says tax may be assessed “at any time”. No clock at all.
That last one is the reason a seller’s aggressive filing is not just a historical curiosity. It is an open liability with no expiry, and if you bought the entity, it is sitting on your balance sheet.
Those windows are what the rest of this comes down to, because each risk below is only as dangerous as how long it can reach.
Worker Misclassification Is the Most Common Inherited Liability
The seller-side problem buyers hit most often is worker misclassification: employees treated as independent contractors to sidestep payroll taxes, benefits, and state labor requirements.
The IRS classification test turns on three things, and none of them is what the contract says. Behavioral control: whether the business directs how the work gets done. Financial control, covering the worker’s own investment, unreimbursed expenses, and whether they can make or lose money. And the relationship itself, including benefits, permanence, and whether the work is core to the business.
For a buyer the exposure has two layers. In a stock purchase, back payroll taxes, penalties, and interest from the pre-close period land on the entity you now own. And even in an asset deal, if you keep the same workforce doing the same work in the same way, you inherit the underlying classification question rather than escaping it.
Cash is the other place seller-side shortcuts tend to hide, and it does something more subtle than create a tax bill.
Unreported Cash Revenue Creates Two Problems at Once
Cash-heavy businesses, meaning restaurants, retail, trades, and service businesses with informal billing, are the highest-risk category here.
Take a seller whose returns show $400,000 in gross revenue when the real number was closer to $550,000. That creates two separate problems for you. The seller has inflated the cash flow you valued the business on, which is a pricing problem. And the business may owe back taxes on the gap, which is a liability problem. They need fixing in different ways.
If your quality of earnings work leans on tax returns without cross-checking bank statements, point-of-sale data, and raw deposit records, you may be modelling off scrubbed numbers. The spread between reported income and actual cash into the bank is one of the first things we look for, and one of the first things a seller’s cut-price accountant had no reason to surface.
Missed Sales Tax Collection Creates State-Level Exposure
Sales tax is handled inconsistently across small businesses, and the gap widened after the Supreme Court’s 2018 decision in South Dakota v. Wayfair, which removed the physical-presence requirement and let states reach remote sellers.
A business selling across state lines may have had collection obligations in states it never registered in, never charged tax for, and never filed a return with. State agencies can typically reach back three to six years on uncollected sales tax, and some states run no statute of limitations at all where the liability was never disclosed.
In an asset purchase, the acquiring entity generally does not inherit pre-close sales tax liabilities, but verify that in the purchase agreement with explicit representations and warranties, backed by indemnification if something surfaces later. A bulk sale clearance from the state tax authority is worth requesting before funds move.
Depreciation Errors Change What You Actually Bought
Where a seller’s accountant fully expensed assets that should have been depreciated, or the reverse, the balance sheet stops reflecting the real asset position.
Buyers who take the fixed-asset schedule at face value, without reconciling it against physical inventory and actual tax basis, sometimes find they paid for assets already fully depreciated off the books, or that bonus depreciation was claimed in a way that misstates remaining useful life.
That feeds straight into your purchase price allocation on Form 8594, which you and the seller both file to report how the price splits across asset classes. If the seller’s basis is not what you assumed, the allocation you negotiated may need revisiting, and changing it after closing is considerably harder than getting it right first time.
How Do You Spot This During Due Diligence?
There are a handful of signals worth treating as a prompt for a closer look.
Returns prepared in consumer software rather than professional tools. Financial statements that will not reconcile cleanly to bank statements. Owner compensation treated differently from year to year with no explanation. Large round-number expenses parked in “consulting” or “other” with nothing behind them.
A seller who cannot produce clean depreciation schedules, has never filed 1099s for contractors, or whose gross margins swing year to year for no business reason is telling you something. None of that necessarily kills a deal. It tells you where the deeper tax analysis needs to happen, and that it needs to happen before you sign rather than after.
What Can Buyers Do to Protect Themselves?
The useful work all happens before the purchase agreement is final.
Representations and warranties about the accuracy of returns, absence of known liabilities, and payroll and sales tax compliance should be specific rather than boilerplate, and carry an indemnification period long enough to matter. Aligning that period with the assessment windows above is the logic worth applying, rather than accepting whatever the first draft says.
Escrow holdbacks are the other practical tool. Leaving a portion of the price in escrow for a period after close gives you somewhere to actually recover from if a liability surfaces. Buyers who skip it because the deal looks clean are betting that the seller’s cut-price accountant did careful work, and that is a bet worth making consciously rather than by default.
If you are working through a target’s tax position and want a second read before you sign, our buy-side diligence work and quality of earnings analysis are built for exactly this.
Reach out and we can look at it with you.
It is a great deal easier to negotiate protection before the deal closes than to recover from a liability you have already inherited.
