How far back does sales tax exposure go?

To the date nexus was created, not the date you noticed it. States generally have no statute of limitations against an unregistered seller who never filed, which is why the lookback can run several years. A voluntary disclosure agreement typically caps that lookback at three or four years and abates penalties, but the tax within the capped period remains due.

What creates economic nexus for a SaaS company?

Crossing a state's sales or transaction threshold into that state, with no physical presence required. Thresholds are set per state and commonly sit at USD 100,000 of sales into the state; some states also use a transaction count, and several have removed the count in recent years. Remote employees, contractors and inventory create physical nexus separately and on their own.

Is SaaS subject to sales tax?

It depends on the state, which is the whole difficulty. Some states tax software as a service outright, some tax it only when downloaded, some treat it as a non-taxable service, and some tax it differently for business and consumer buyers. A nexus study that assumes one answer nationally produces the wrong number in both directions.

Should we register or use voluntary disclosure?

Register where the exposure period is short and use voluntary disclosure where it is long, then check whether the state disqualifies you. Straight registration is faster and cheaper administratively but exposes the full historic period. A VDA caps the lookback and abates penalties, but most states refuse one where tax was actually collected from customers and not remitted, and all of them refuse one after they have contacted you.

What happens to sales tax exposure in an acquisition?

It is normally handled through an escrow or holdback rather than killing the deal. Acquirers price a quantified, disclosed exposure. What they struggle to price is an unquantified one, which is why the schedule matters more than the number on it.

Do we need exemption certificates if the customer is exempt?

Yes, and the certificate has to be on file before the untaxed sale, not obtained afterwards. In an audit, the seller carries the burden of proving why tax was not charged. A verbal claim of resale or exempt status with no certificate behind it usually results in the tax being assessed against the seller.

SaaS · 🇺🇸 United StatesScenario

How multi-state sales tax nexus is remediated before diligence

Unregistered economic nexus is remediated state by state, by dating each threshold crossing from raw transaction data and then choosing, per state, between a voluntary disclosure agreement and a standard back registration. This is an illustrative example of how Salt approaches that work, using a Series A SaaS company as the profile.

Ask how we'd handle this

Scenario — an illustrative example of how Salt approaches this problem. Not a description of a specific client engagement.

The business shape it describes: US SaaS, Series A, around 4,200 transactions a month.

Scenario covers: Multi-state sales tax nexus review, retrospective registration and back filing, with bookkeeping and controller support
Software it assumes: QuickBooks
Jurisdiction: United States
Sector: SaaS

The setup

Take a US SaaS company at Series A, selling self-serve across most states, with a bookkeeper who registers and files in the home state only.
Sales tax has been treated as one national obligation. A Series B diligence request asks for nexus analysis by state, and none exists.

What usually turns out to be wrong

Economic nexus thresholds crossed in states where nothing was registered. Since South Dakota v. Wayfair, each state sets its own trigger — commonly USD 100,000 of sales into the state, sometimes with a separate transaction count that several states have since removed.
Native QuickBooks tax settings applying one blended rate rather than rates determined at the jurisdiction level, which in home-rule states means city and county rates were never applied at all.
Software subscription revenue taxed inconsistently. Whether SaaS is taxable is a state-by-state question, not a national one.
Resale customers who claimed exemption verbally, with no exemption certificate on file to support the untaxed sale.

How this would be worked

Build a nexus study from raw transaction data rather than from what was previously filed, dating the exact month each state's threshold was crossed.
Score each state separately: lookback length, penalty exposure, whether the state offers a voluntary disclosure agreement, and whether the tax was collected but unremitted, which usually disqualifies a VDA.
Register in the states where a straight registration is cheaper, and open voluntary disclosure in the states where the lookback justifies it.
Prepare returns for each open period against reconciled figures. Where a state requires a licensed representative to negotiate, that stays with the client's own CPA or state and local tax adviser.
Connect automated rate determination so the ledger and the returns reconcile without a manual adjustment each period.
Add exemption certificate collection to the sales workflow, with the certificate stored against the customer record before the first untaxed invoice.

Why we'd be the right fit

Dating each threshold crossing means working forward from transaction data, not backwards from filed returns. That judgement is the work; the registrations themselves are clerical.
The VDA decision is where the money is. A state where tax was collected and not remitted is usually outside voluntary disclosure entirely, and treating all states as one programme gets that wrong.

What the business would be able to do

The company would be able to hand an acquirer a dated, state-by-state exposure schedule instead of an unanswered question, which changes a discovered problem into a disclosed one.
Sales tax would be determined at the jurisdiction level at the point of sale, so the return reconciles to the ledger without a manual adjustment.
Exemption certificates would exist for every untaxed sale before the invoice is issued, rather than being requested during an audit.

What we'd flag

Voluntary disclosure abates penalties and limits the lookback. It does not remove the underlying tax, and on B2C or unbilled B2B sales that tax was never collected from the customer, so it comes out of margin. Finding this earlier is always materially cheaper.

Answers

How multi-state sales tax nexus is remediated before diligence

Where this applies

BookkeepingService Sales Tax · VAT · GSTService All services in United StatesUS GAAP More scenarios42 illustrative, labelled examples

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