The investment banker is engaged. The CIM is drafted. You're weeks away from fielding LOIs for the company you've spent years building. And at some point in the next few months, a buyer's tax team will pull your sales tax records, run a nexus analysis, and produce a number.
The question isn't whether they'll find something. It's whether you already know what they'll find, and whether you've had any time to do something about it.
Sellers who wait for buyer diligence to surface sales tax problems lose control of the narrative entirely. They end up reacting to someone else's exposure estimate, negotiating from a weakened position, and frequently absorbing a purchase price reduction or escrow holdback that could have been avoided. Or at least minimized.
This article walks through exactly what buyers look for in your sales tax records, what the financial stakes are when they find issues, and what your options are if you start early enough to actually do something about it.
The Buyer's Tax Team Has a Checklist. Here's What's On It.
Before you can prepare for diligence, you need to understand what's coming. A buyer's sales tax review isn't a casual glance at your returns. It's a systematic, adversarial examination by people whose job is to find problems and use them in negotiation.
Here's what their checklist typically includes:
Nexus footprint vs. registration list. Buyers will map where your company actually has nexus against where you're registered and filing. This means analyzing both physical presence (offices, employees, warehouses, inventory) and economic nexus based on revenue thresholds by state. Any gap between where you should be filing and where you are filing gets treated as unquantified exposure.
Return history and filing completeness. Are returns filed on time in every registered state? Any gaps, amended returns, or delinquent periods get flagged immediately. A pattern of late filings or missing periods signals broader compliance issues.
Taxability treatment. Are the right products and services being taxed correctly? This is especially scrutinized for SaaS and software companies (more than two dozen states tax SaaS in some form as of 2026), digital goods, services, and mixed-transaction businesses. Incorrect taxability treatment that's been running for years creates cumulative exposure that compounds quickly.
Exemption certificate files. Buyers will ask for documentation proving that exempt sales were actually exempt. Missing, expired, or incomplete certificates on file are one of the most common audit triggers found during diligence. If you can't prove an exemption was valid, the buyer assumes it wasn't.
Audit history and open state notices. Any outstanding notices, open audits, or assessments survive the deal and become the buyer's problem. They will price accordingly, often conservatively.
Use tax compliance. This one is often overlooked by sellers but never by buyers' tax teams. If your company hasn't been self-assessing use tax on taxable purchases, that's a separate exposure line that gets added to the total.
Here's the key point: buyers' estimates of exposure are deliberately conservative. They're not trying to get to the right number. They're trying to protect themselves from worst-case scenarios. If you haven't done your own analysis, you'll be responding to their number, not presenting yours.
What "We Found an Issue" Actually Costs You
When a buyer's diligence team surfaces material sales tax exposure, the deal doesn't necessarily die. But it shifts. And the shift almost always favors the buyer.
Here are the typical outcomes, in rough order of how painful they are for the seller:
| Outcome | What It Means for the Seller |
| Purchase price reduction | Buyer adjusts the offer downward by the estimated exposure amount. You negotiate against their number, not yours. |
| Escrow holdback | A portion of proceeds (commonly 5-15% of deal value, sometimes more for specific tax issues) is held back post-close, released only after the liability is resolved. You've technically "gotten" the money but can't use it for 12-24 months. |
| Indemnification clause | You remain personally liable for pre-close sales tax liabilities for a defined survival period (typically 18-24 months, sometimes longer for tax reps). |
| Special tax escrow | If exposure is large and specific, buyers may demand a separate escrow bucket just for the tax issue, sized at 130-150% of estimated liability. |
| Deal collapse | In deals where exposure is material relative to deal size and neither party can agree on terms, transactions fall apart. This happens more often than sellers expect. |
The common thread across all of these outcomes is that the seller is reacting. Every one of these scenarios involves the buyer having the information while the seller catches up. That's a structurally weak negotiating position.
And it was avoidable.
We recently worked with a seller who identified and resolved over $500,000 in exposure before it hit the closing table. The difference wasn't luck. It was timing. They looked at their records before a buyer did, quantified the issue on their own terms, and presented a clean resolution rather than scrambling to respond to someone else's estimate.
Why "We File in Our Home State" Isn't the Answer Anymore
The most common misconception we see from sellers: filing in the states where you have offices or warehouses equals compliance.
That hasn't been true since 2018.
What changed: The Supreme Court's South Dakota v. Wayfair decision established economic nexus. Now, selling into a state above certain revenue thresholds (typically $100,000 in sales or 200 transactions per year) creates an obligation to collect and remit sales tax, even with zero physical presence in that state.
What this means for growing companies: Most businesses that scaled over the past several years crossed economic nexus thresholds in multiple states without ever formalizing compliance in those states. The company files where it has offices. The exposure is where it has customers.
Why the math matters: Unlike income tax, sales tax is a gross revenue tax. It can't be offset by operating losses. A company generating $15 million in revenue with a 6% average rate across states where it hasn't been filing is looking at significant potential exposure, regardless of whether the company is profitable.
Who's at elevated risk: Sellers who grew fast, expanded into new markets, changed their product mix (especially toward digital or SaaS), or went through any prior change of ownership are at particularly elevated risk. Each of those transitions likely triggered new nexus obligations that may not have been addressed.
The timing reality: sellers who start this analysis 6-12 months before going to market have meaningful options. Sellers who start after the LOI is signed are mostly managing damage.
If you're curious what buyers will see when they look at your records, that's exactly what a sell-side diligence engagement is designed to answer.
The Earlier You Look, the More Options You Have
Timing is the entire variable that separates a seller who controls the narrative from one who doesn't. Here's what's possible at different stages.
If You're 6-12 Months Out from Market
Full runway. You can:
- Commission a nexus study to map your actual exposure footprint across all states
- Quantify prior-period liability with penalties and interest included so you know the real number before anyone else does
- File Voluntary Disclosure Agreements (VDAs) proactively in states with meaningful exposure
A quick note on VDAs: this is a program offered by most states that lets companies voluntarily come forward, pay what they owe, and get penalties waived in exchange. Penalties can run 25-50% of base tax owed, so this isn't a small benefit. VDAs also typically limit the look-back period to 3-4 years rather than indefinitely. And critically, VDAs can often be initiated anonymously, meaning you explore the terms before disclosing the company's identity.
Learn more about how VDAs work on our registrations and VDAs page.
You can also use this window to:
- Get your exemption certificate files in order
- Build a clean compliance track record in the months before diligence begins
- Document everything so buyers see the work you've done
If You're Already in Process (LOI Signed or Imminent)
The window is tighter but options still exist:
- A rapid-turnaround nexus and exposure analysis at least gives you your own number before the buyer presents theirs
- VDAs can still be negotiated as part of deal terms, with seller and buyer agreeing on who funds the liability and how the process unfolds post-close
- You can negotiate from a position of awareness: "We're aware of this, here's our quantification, here's our remediation plan" is a fundamentally different conversation than simply reacting to the buyer's estimate
Here's the contrast to keep in mind: a VDA before going to market means you controlled the process, limited the look-back, eliminated penalties, and presented a clean resolution to buyers. A VDA forced by buyer diligence means the buyer typically controls the process, sets the escrow amount, and you fund a liability that may have been smaller if you'd caught it first.
Sell-Side Sales Tax Checklist: What to Review Before You Go to Market
Whether you're 12 months out or already fielding interest, here's what to review.
12+ Months Before Market
- Run a nexus analysis: where do you have economic or physical nexus vs. where are you registered?
- Pull your full state registration list and filing history and look for gaps
- Audit your taxability setup: are all product and service lines treated correctly by state?
- Review exemption certificate files for completeness and currency
- Assess use tax compliance on your own taxable purchases
6-12 Months Before Market
- Quantify prior-period exposure in unregistered states, including penalties and interest
- Evaluate VDA eligibility in all states with meaningful exposure
- File VDAs anonymously where appropriate to limit look-back and eliminate penalties
- Remediate any exemption certificate gaps
- Establish clean, forward-going compliance in all newly registered states
- Document everything. Buyers will want to see the work.
At or After LOI
- Commission a rapid exposure analysis if not already done. You need your own number.
- Negotiate VDA rights and seller/buyer funding split into purchase agreement terms
- Ensure all open state notices and audits are disclosed and accounted for in deal terms
- Review indemnification survival periods for sales tax reps. Know what you're agreeing to.
- Work with a sales tax specialist, not just your general M&A counsel, on the SALT provisions
If you're also advising buyers on transactions, you may find our companion piece helpful: Sales Tax in M&A: What Every CFO Needs to Know Before the Deal Closes.
You Built Something Worth Selling. Don't Let Sales Tax Erode What You Walk Away With.
Sales tax exposure is one of the few deal risks that is genuinely fixable given enough runway. The sellers who protect their valuation are the ones who looked at their records before a buyer did. They knew their number. They cleaned up what they could. And when diligence started, they weren't surprised.
The difference between a seller who negotiates from strength and one who scrambles to respond comes down to timing and preparation. A clean sales tax record heading into a transaction isn't luck. It's the result of understanding what buyers will look for, quantifying exposure on your own terms, and taking action while you still have options.
If you're 6 to 24 months from a potential sale, that's the right window. Starting now means you can control the process, limit your look-back periods, eliminate penalties through VDAs, and present a clean compliance story to buyers. Waiting means you'll be reacting to someone else's estimate with someone else's timeline.
The Sales Tax People work with business owners and their advisors on sell-side sales tax preparation. From initial nexus analysis through VDA resolution and transaction support, we help sellers understand what buyers will find and address it before it becomes a negotiating chip.
Schedule a free "What's Next" call to talk through your situation with a sales tax expert. No fees, no pressure. Just a clear picture of where you stand and what your options are.
People Also Ask
Buyers and their tax advisors typically run a structured sales tax diligence review that covers five key areas. First, nexus — they map every state where the seller has customers, employees, inventory, or contractors and compare that against the states where the seller is currently registered and filing. Second, taxability — they review how the seller has classified its products and services for tax purposes in each state and whether those classifications are correct. Third, exemption certificates — they sample the seller's exempt transaction history and request supporting documentation for each one. Fourth, use tax — they review the seller's purchasing and accounts payable records to assess whether the company has been self-assessing and remitting use tax on taxable purchases where no sales tax was charged. And fifth, filing history — they look for gaps, late filings, open audit periods, and any prior state correspondence that signals known exposure.
Sales tax exposure discovered during diligence affects deal economics in three primary ways. The most direct impact is a purchase price reduction — the buyer adjusts their offer downward to account for the liability they are about to absorb. The second is an escrow holdback — a portion of the purchase price is withheld at closing and held in escrow, typically for 12 to 24 months, pending resolution of the identified exposure. The third is indemnification provisions that require the seller to cover any sales tax liabilities that surface post-close up to a negotiated cap and duration. In all three cases, the seller receives less money than they would have without the exposure. Because buyers typically make worst-case assumptions when they quantify exposure mid-diligence — there is no time for precision — the amount withheld or reduced often exceeds the actual liability by a significant margin. Sellers who have already quantified and remediated their exposure before going to market avoid this dynamic entirely.
Sell-side sales tax due diligence is the process of a seller proactively reviewing their own sales tax compliance — before going to market — to identify and address any exposure before a buyer's team finds it during their own diligence. It mirrors what the buyer's tax advisors will do, but with the significant advantage of time: a seller conducting their own review months before the deal process begins has options — Voluntary Disclosure Agreements, retroactive registrations, amended filings — that a seller scrambling to respond to buyer findings mid-diligence simply does not have. Sell-side diligence also gives the seller control of the narrative: instead of reacting to an exposure estimate produced by the buyer's team under time pressure, the seller can present a clean, documented compliance position that the buyer's team confirms rather than discovers. In a competitive deal process, that difference in positioning can be worth significantly more than the cost of the diligence itself.
Buyers typically look back three to four years — the standard state audit lookback period for registered filers. However, for states where the seller was never registered and never filed, the statute of limitations never started running, which means a buyer's diligence team can theoretically look back to the very first day the seller had a nexus obligation in that state. For SaaS companies, e-commerce businesses, and companies with remote employees that expanded into new states over the past several years without registering, this can mean exposure stretching back five, seven, or even ten or more years in certain states. This is why nexus history — not just current filing status — is one of the first things buyers examine. A seller with clean, documented registrations and timely filings can generally limit the lookback to the standard statutory period. A seller with registration gaps in multiple states faces a much broader exposure window.
The five most common findings in sales tax diligence are: unregistered states where the seller crossed economic nexus thresholds without registering — especially common for SaaS, software, and subscription businesses that grew quickly across state lines; incorrect taxability treatment on digital goods, services, or bundled offerings that are taxable in some states but were treated as exempt across the board; missing or invalid exemption certificates on B2B transactions that were recorded as exempt without adequate documentation; use tax gaps on the seller's own purchases, particularly software subscriptions, equipment, and out-of-state vendor invoices; and remote employee nexus — employees hired in new states who triggered physical nexus that was never identified or registered. These five issues are not random — they are the predictable byproducts of a business that grew quickly and prioritized revenue over compliance infrastructure, which describes the majority of the companies that go through a sale process.
The remediation process starts with a nexus study — a state-by-state analysis of where the business has had obligations, when those obligations began, and what was and was not filed. For states where the seller has unaddressed historical exposure, Voluntary Disclosure Agreements are typically the most effective tool: they allow the seller to come forward proactively, cap the lookback period, and eliminate or significantly reduce penalties in exchange for registering and filing going forward. VDAs must be filed before the state makes first contact, which is one more reason why starting before the deal process begins is critical. In states with shorter exposure windows or where the liability is small, the seller may choose to simply register prospectively and disclose the historical gap to the buyer rather than file a VDA. For taxability misclassifications and exemption certificate gaps, the remediation involves correcting the treatment going forward and documenting the defensible position for the periods already filed.
An escrow holdback is a portion of the purchase price that is withheld at closing and placed in an escrow account, to be released to the seller only after identified liabilities — including sales tax exposure — have been resolved or confirmed to be less than the estimated amount. In the context of sales tax, a holdback is typically used when the buyer's diligence team identifies exposure that has not been remediated but the parties still want to close the deal. The holdback provides the buyer with funded protection against a liability that may not be fully quantified at closing. For the seller, a holdback means receiving less cash at close — and potentially waiting 12 to 24 months before the escrowed funds are released, depending on the resolution timeline. If the seller can demonstrate that the actual liability is lower than the buyer's worst-case estimate, they may be entitled to recover the excess from escrow. This recovery process takes time and resources that could be avoided entirely by addressing the exposure before the deal process begins.
