8 Sales Tax Compliance Scenarios for Cross-Border Sellers

About these scenarios. The eight situations below are illustrative composites, not real client engagements. Each is built from the patterns we see most frequently across cross-border seller work — the situation, the trigger, and the typical fix. They are presented to show the categories of problems we solve and the shape of the resolution. They are not testimonials, and no individual client is described.

Most sales tax problems are not unique. They are variations of eight recurring patterns. A UK Amazon FBA seller with inventory in 31 states has the same structural exposure as an Australian one. A SaaS startup tripped up by Vermont’s 2024 reversal has the same root cause as one tripped up by Louisiana’s 2025 expansion. The seller profiles differ; the underlying problem rarely does.

This page walks through eight of those recurring patterns. For each one, you’ll see:

• The seller profile we typically see it in
• What they were doing themselves before they contacted us
• Where the approach broke down
• The financial and operational exposure
• How a done-for-you service like ours would resolve it

If one of these looks like your situation, the resolution path is well-trodden. The earlier in the timeline we get involved, the cheaper the cleanup.

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How to read this page

Each scenario follows the same structure so you can scan for the one that fits your situation. The fixes described are not hypothetical — they are the standard workstreams in our Phase 1 setup and Phase 2 ongoing service. Pricing ranges are typical, not promises; every engagement is quoted after a discovery call and a look at the actual data.

Two things to keep in mind as you read:

1. Sales tax is jurisdictional. Every state writes its own rules, sets its own thresholds, and runs its own audits. There is no federal sales tax in the US. What’s safe in one state can be a registration breach in the next.
2. Inventory creates exposure that revenue can’t see. Almost every scenario below has the same root cause: physical or economic nexus was triggered months or years before anyone noticed. The cure is always cheaper than the symptom.

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Scenario 1: UK Amazon FBA seller with inventory in 31 states and zero registrations

The seller

A UK-incorporated consumer brand — health supplements, beauty products, pet accessories, the typical FBA categories. Two to three years on Amazon US. Annual US revenue between $400K and $1.5M, mostly through Amazon FBA, a small portion through a Shopify storefront fulfilled via Amazon’s Multi-Channel Fulfillment. No US LLC, no US employees, no US office.

What they were doing

Relying on Amazon’s marketplace facilitator collection. Amazon collects and remits sales tax on the FBA sales — so the seller assumed they had no compliance burden. They had not registered for sales tax in any US state, not filed any US federal return, and not provided an updated Form W-8BEN-E in 18 months. Their UK accountant handled UK obligations and treated US activity as out-of-scope.

Where it broke

The assumption is half-right and half-wrong. Amazon’s marketplace facilitator collection does cover the collection and remittance obligation on Amazon-platform sales. It does not cover everything else.

What Amazon’s collection doesn’t cover:
– Physical-presence nexus from FBA inventory. Amazon’s automated distribution had spread inventory across roughly 30 states. Each of those states has a physical-presence sales tax nexus from the inventory, irrespective of the dollar volume. Most of those states still require the seller to register, file, and report — even when 100% of sales were marketplace-facilitated.
– State income / franchise tax. The inventory exceeds PL 86-272 protection. Some states impose a corporate income or franchise tax on the seller’s apportioned share of US-sourced income.
– The Shopify direct-channel sales. Amazon’s MF collection does not extend to Shopify checkout, even when Amazon fulfils the order. The seller is the merchant of record. Once nexus exists in a state, every dollar of direct sale into that state should have had tax collected from dollar one.
– The federal layer. A foreign corporation selling into the US is required, under most treaties, to file an annual protective Form 1120-F together with Form 8833 to document the no-permanent-establishment treaty position. Failing to file forfeits the deduction safe harbour under Treas. Reg. §1.882-4 and exposes the seller to a $10,000 penalty per Form 8833 failure under IRC §6712.

The exposure

• Three to five years of unfiled state returns across 30+ states (most states allow a zero-return registration, but the registration itself is mandatory in many).
• Uncollected sales tax on the Shopify direct channel — typically a small dollar amount but a multi-year liability with penalty stacking.
• Potential state income / franchise tax exposure in the handful of states whose corporate income tax does not conform to the federal treaty exemption. The list is short but matters; it has to be checked state by state for the seller’s actual inventory footprint.
• Three to five years of unfiled protective Form 1120-F filings — each one a potential $10K Form 8833 penalty.
• Risk of 30% gross withholding by Amazon if the W-8BEN-E is allowed to expire (validity is generally three years from signing).

How we’d resolve it

1. Pull the Amazon Seller Central FBA inventory report to fix the actual state footprint.
2. Refresh the W-8BEN-E with Amazon and any other US payor, citing the correct treaty article and Limitation on Benefits code.
3. Back-file protective Form 1120-F + Form 8833 for each open year — typically the last three.
4. Run a state-by-state nexus and marketplace-facilitator analysis to identify which states require seller registration despite full MF collection, which exempt the marketplace seller, and which have outstanding direct-channel exposure.
5. Pursue Voluntary Disclosure Agreements in states where the direct-channel exposure is material — the standard VDA package limits lookback to 3–4 years and waives penalties.
6. Register, automate, and file in the remaining states going forward, with the registration footprint sized to the seller’s actual nexus rather than to an over-cautious “everywhere” default.
7. Establish a monthly compliance rhythm so the seller never gets surprised by the next state expansion.

If this is you

The fix is well-understood and the timeline is usually 60–90 days for Phase 1 cleanup. The earlier you start, the smaller the lookback. See our foreign seller sales tax guide for the full background.

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Scenario 2: Australian Shopify brand at $1.8M revenue, crossed economic nexus in 12 states without realising

The seller

An Australian DTC brand — apparel, accessories, or beauty — selling through Shopify with US fulfilment from a single third-party logistics warehouse in one US state. No Amazon. Annual US revenue grew from $300K to $1.8M over two years. Founders are aware of US sales tax in general terms but have not done a formal nexus review.

What they were doing

They had heard of “the $100,000 rule” and assumed it applied uniformly. They had registered in their 3PL state (correctly — physical presence). They had configured their Shopify checkout to collect sales tax in that state and in two additional states where they had visibly crossed $100K in revenue. They believed they were compliant.

Where it broke

“The $100,000 rule” is the most-quoted, least-uniform rule in US sales tax. The actual thresholds, what counts, and the measurement period vary state by state.

• California’s threshold is $500,000 in combined sales — much higher than the default, but California also counts marketplace sales in the seller’s threshold, which trips up sellers that do mix channels.
• Texas requires $500,000 in Texas-sourced gross revenue in the preceding 12 calendar months.
• New York requires both $500,000 in receipts AND more than 100 transactions — the only major state still using a dual prong.
• A dozen states have repealed the 200-transaction count entirely, leaving only the dollar threshold. Others retain it.
• Some states measure on gross sales, some on taxable sales, some on retail sales only. A B2B-heavy seller with substantial wholesale revenue can cross the threshold in a “gross sales” state and not in a “taxable sales” state on the same data.
• Measurement periods vary: prior calendar year, current and prior calendar year, or rolling 12 months.

The Shopify checkout configuration was based on a single rule of thumb. The actual nexus footprint, on a state-by-state analysis, was 12 states — most of them well past the threshold for 6 to 14 months before anyone looked.

The exposure

• Back tax on every taxable sale in each of the 12 states from the date the threshold was crossed.
• Monthly interest accruing at each state’s statutory rate — usually a per-month percentage that compounds the longer the exposure runs.
• Penalties on top of the interest, ranging from modest late-filing fees in some states to severe percentages of the tax due in others.
• Tax is paid out of the seller’s margin, not collected from the customer at the time of sale.
• Trailing nexus rules mean that even if revenue dips below threshold, the obligation continues to the end of the current calendar year and the entire following calendar year in most states.

How we’d resolve it

1. Pull 24 months of Shopify sales data broken out by ship-to state, dollar amount, and transaction count.
2. Separate direct-channel sales from any marketplace or wholesale lines, since most states treat them differently for threshold purposes.
3. Apply each state’s specific threshold, definition (gross/taxable/retail), and measurement period to identify which states have been over the line, when, and for how long.
4. Quantify the exposure state by state — uncollected tax, accrued interest, projected penalty.
5. For material exposure, file Voluntary Disclosure Agreements to limit lookback and waive penalties.
6. Register and configure collection going forward, with the Shopify tax engine set up correctly per state (including sourcing rules — destination vs origin — and product taxability mapping).
7. Set up a monthly nexus monitor so future threshold crossings trigger registration before the back-tax clock starts.

If this is you

The single most expensive mistake we see is delay. Once you suspect you’ve crossed a threshold, the right move is a 5-day nexus review — not another 90 days of “we’ll get to it.” See our economic nexus thresholds by state chart for the current state-by-state numbers.

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Scenario 3: B2B SaaS startup ambushed by three state rule changes in 18 months

The seller

A South African or European B2B SaaS company. Mid-market customer base across 30+ US states, annual contract values from $5K to $80K, total US revenue $1M–$5M. Sells through its own checkout (Stripe), not through a marketplace. Has a US C-corp for banking and contracting purposes but no US office or employees.

What they were doing

They had done a one-time sales tax review when they crossed $1M and concluded that SaaS was non-taxable in most of their customer states. They registered in five clearly-taxable states (New York, Texas, Pennsylvania, Massachusetts, Washington) and set up tax collection in their checkout for those five.

That snapshot was correct at the time. SaaS taxability is the most volatile area of US sales tax, and it changed underneath them.

Where it broke

Between mid-2024 and the end of 2025, three of the seller’s top revenue states moved:

• Vermont reversed a long-standing SaaS exemption effective July 1, 2024, with limited notice. Customers there became taxable mid-contract.
• Louisiana made SaaS taxable effective January 1, 2025.
• Washington’s SB 5814 substantially expanded its SaaS and digital services tax base effective October 1, 2025, with transitional rules for contracts signed before that date.

In addition, a New York appellate decision in the Beeline.com matter reinforced the state’s position that web-portal SaaS is taxable as prewritten software — a position that, while not new, hardened the state’s audit posture.

The seller did not catch any of these changes in time. By the time they noticed, they were nine to fourteen months under-collecting in three states with significant customer concentration.

The exposure

• Uncollected tax in three states going back to the effective date of the rule change.
• The tax is now owed out of margin, since the seller did not collect it from customers at invoice time.
• Risk of customer disputes when belated invoices for the back-tax period are issued.
• Audit risk increases sharply once a state is aware of a registered seller that under-reported.

How we’d resolve it

1. Quantify the under-collection in each state, by month, by customer.
2. Decide per state whether to invoice customers for back-tax or absorb it — typically a function of customer relationship strength, contract language, and the dollar materiality.
3. For absorbed back-tax, file amended returns and pay with interest, in most cases avoiding penalty under the seller’s existing registration.
4. Update the tax engine and product taxability mapping to reflect current rules in all 45 sales-tax states, with a particular eye on the eight states that have moved in the past 24 months.
5. Subscribe the engagement to a monthly SaaS taxability monitor — the most volatile single area of US sales tax. Every change is flagged within days and assessed against the seller’s specific footprint.
6. Re-paper customer contracts where appropriate to make the seller’s right to pass on future tax changes explicit.

If this is you

SaaS sellers should never rely on a one-time taxability review. Every quarter, two to four states change their position. The monitoring is the deliverable, not the initial set-up. See our SaaS sales tax by state guide for the current matrix.

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Scenario 4: Drop-shipper whose California margin disappeared overnight

The seller

A US-based or Canadian-based online retailer that does not hold inventory. Customer orders are forwarded to one or more wholesalers who ship directly to the end customer. Revenue $500K–$3M, multi-state customer base.

What they were doing

The retailer had registered for sales tax in their home state and in three other states where they had visible nexus. They held a resale certificate (multi-state MTC Uniform Resale Certificate) and provided it to their wholesalers. They believed this discharged the obligation.

Where it broke

The drop-ship problem is the most expensive misunderstanding in retail sales tax, and California is its archetype.

Under California’s CDTFA Regulation 1706, when a wholesaler ships product into California on behalf of an out-of-state retailer that is not registered in California, the wholesaler is treated as the retailer of record for that transaction. The wholesaler must collect California sales tax — and they will collect it from the only party they have a billing relationship with, which is the out-of-state retailer.

The retailer, who did not collect tax from their California customer at the time of sale, now eats the tax on every California-shipped order. On a thin-margin product, the entire drop-shipped California channel can become loss-making.

The same pattern, in slightly varied form, exists in Connecticut, Florida, Hawaii, Maryland, Massachusetts, and Mississippi historically. The retailer did not know they were exposed in any of them.

The exposure

• Wholesaler invoices include California sales tax line items, retroactive in some cases.
• Direct margin hit on every drop-shipped order shipped into the affected states.
• Resale certificates from the retailer’s home state are not honoured in the drop-ship destination states — the retailer must be registered in the destination state and produce a destination-state certificate (or in some states, the wholesaler may accept the home-state certificate only if specific substantiation is provided).

How we’d resolve it

1. Map the transaction flow — for each customer state, identify which wholesaler ships, and whether the retailer or the wholesaler has nexus in that state.
2. Register the retailer in each drop-ship destination state where the volume justifies it, so the retailer can provide a destination-state resale certificate.
3. Build a resale certificate workflow — collect, store, and update certificates from the retailer to each wholesaler, in the correct state-specific format.
4. Reconfigure the checkout to collect sales tax in each newly-registered state from the customer, so the cost is no longer absorbed by the retailer.
5. Audit existing wholesaler invoices to confirm tax is being applied correctly going forward and challenge any retroactive line items that lack a defensible basis.

If this is you

Drop-shipping engagements are higher-complexity than typical FBA or DTC work. The mapping is the deliverable, and it should be the first step before any other action.

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Scenario 5: South African wholesaler with $2M in B2B gross sales — registered in the wrong states

The seller

A South African manufacturer of components, ingredients, or industrial supplies selling B2B into the US. All US customers are resellers or manufacturers (no end consumers). Annual US revenue $1.5M–$4M, spread across 10–15 states, all customers exempt from sales tax with valid resale or manufacturing-exemption certificates.

What they were doing

The seller’s US accountant, looking at the gross revenue, concluded that the seller had economic nexus in multiple states and registered them in all of those states. The seller now files monthly sales tax returns in 12 states. Every return is a zero return because every customer is exempt. The engagement is costing the seller $700–$1,000 a month and the seller is wondering what they paid for.

Where it broke

The threshold definition varies by state. Several states measure economic nexus on gross sales, including exempt and wholesale revenue. Others measure on taxable sales only. A few measure on retail sales only.

For a B2B-only seller:

• In a gross-sales state, the seller may have nexus despite zero taxable sales. Registration may still be required, but the filings are zero returns.
• In a taxable-sales state, the seller has no nexus and no obligation.
• In a retail-sales state, the seller has no nexus and no obligation.

The accountant applied a uniform rule and registered the seller in states where no obligation existed. The seller is now bearing the compliance cost of registrations that should never have been opened, and is locked into trailing-nexus filing obligations even if they de-register.

The exposure

• Direct compliance cost — monthly returns in states that should never have been on the list.
• A registered seller is on the state’s radar. Even with zero returns, the state can audit.
• De-registering is not instant. Most states require continued filing through trailing-nexus periods (typically end of current calendar year plus the following one).

How we’d resolve it

1. Re-run the nexus analysis per state with the correct threshold definition — gross vs taxable vs retail vs SaaS-specific.
2. Identify the states where the registration is voluntary, premature, or unnecessary, and the states where it is correctly required.
3. Build an exemption-certificate workflow for every B2B customer — current, signed, state-specific, dated, indexed. This is the single most-audited area for B2B sellers, and a complete certificate file is the difference between a clean audit and a six-figure assessment.
4. De-register where appropriate, with the correct closing returns, and maintain registration where required, with zero returns filed monthly.
5. Shift the engagement scope from “12 states of monthly returns” to “the right states plus an audit-ready exemption certificate library.” Lower fee, higher value.

If this is you

B2B sellers are over-registered as often as DTC sellers are under-registered. The certificate file is the work product that protects the seller in an audit — not the volume of zero returns filed.

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Scenario 6: Hybrid brand selling both a physical product and a SaaS subscription

The seller

A company that sells a connected physical product (consumer hardware, fitness device, IoT product) bundled or paired with a SaaS subscription. The physical product is shipped from a US 3PL. The SaaS is delivered through Stripe checkout. Customer base in 40+ states. Revenue $2M–$10M.

What they were doing

The seller treated the two product lines as separate compliance domains. The physical product was registered for sales tax in the 3PL state plus the economic-nexus states (10 of them). The SaaS subscription was registered nowhere on the assumption that “SaaS is mostly not taxable.”

Where it broke

Two compounding errors:

• The SaaS line is taxable in roughly 20 states, several of which overlap with the physical-product registration footprint. The seller had nexus in those states from the physical product but was not collecting tax on the SaaS revenue.
• Bundled transactions trigger different rules in different states. In Texas, software bundled with non-taxable services is taxable in full unless the non-taxable component is more than 5%. In Pennsylvania, separately-stated charges are treated separately. In New York, the substance-over-form test applied in Beeline.com and similar cases looks at the dominant purpose of the bundle.

Compounding the error, when the SaaS subscription is bundled into the physical product purchase at checkout, the entire bundled price can be reclassified as taxable software in some states — meaning the physical-product-only registration is also under-reporting.

The exposure

• Under-collected SaaS sales tax in roughly 15 states across multiple years.
• Under-collected bundled-transaction sales tax in the states where the bundle is reclassified.
• The seller had a tax engine in place but it was configured only for the physical product line.

How we’d resolve it

1. Map every SKU and every subscription tier to the correct product tax code in each state.
2. Quantify under-collection for both lines and the bundle separately.
3. For material exposure, pursue VDAs in the affected states.
4. Reconfigure the tax engine to handle the SaaS line, the physical line, and the bundle correctly per state — including separately-stated invoice formatting where it changes the answer.
5. Update contracts and checkout to ensure the customer-side communication matches the tax treatment.
6. Subscribe the engagement to SaaS taxability monitoring as in Scenario 3.

If this is you

Hybrid hardware-plus-SaaS brands are the single most common source of bundled-transaction under-collection. Treating the two as separate compliance problems is the root cause. The fix is to treat them as one problem with state-specific rules.

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Scenario 7: Foreign seller whose Amazon payouts dropped 30% with no warning

The seller

A foreign-incorporated seller — UK, Australia, New Zealand, Ireland, Canada, South Africa — selling on Amazon US. Active for two to five years. The original Amazon onboarding included a W-8BEN-E claiming treaty benefits. The form was never refreshed.

What they were doing

Operating on the same Amazon Seller Central setup they had at onboarding. No US filings, no US presence, treaty-based assumption of no US tax.

Where it broke

W-8BEN-E is generally valid for three years from the date of signing, subject to change-in-circumstance rules. When it expires, Amazon — like any US payor — has a legal obligation under the chapter 3 NRA withholding rules to begin withholding 30% on gross payments to the foreign seller until a new, valid W-8BEN-E is on file.

The seller noticed the payouts had dropped about 30% across a payment cycle, contacted Amazon, and was directed to refresh the W-8BEN-E. By the time they did, several payment cycles had been withheld and the withheld funds were now in IRS hands, recoverable only through a formal refund mechanism (filing a Form 1120-F claiming refund of over-withholding).

The exposure

• 30% of gross payouts withheld for the period the W-8BEN-E was lapsed.
• Cash-flow gap that, for a seller with thin operating margins, can be existential.
• Refund requires filing Form 1120-F, which the seller likely was not filing on a routine basis — meaning the refund claim sits behind a multi-year compliance cleanup.

How we’d resolve it

1. Immediate refresh of the W-8BEN-E with Amazon, citing the correct treaty article and LOB code, to stop the bleeding.
2. Confirm refresh in every other US payor relationship — Stripe, Shopify Payments, banks, software vendors — to prevent the same issue elsewhere.
3. File Form 1120-F for each affected year with treaty-based refund claims, supported by Form 8833 disclosing the treaty position.
4. Establish a W-8BEN-E expiration tracker so the next refresh date is calendared and actioned 90 days in advance.
5. Address the historical compliance gap — the protective Form 1120-F filings for prior years should have been on file anyway. The refund claim is folded into the broader cleanup.

If this is you

This is one of the cheapest problems to prevent and one of the most expensive to live with. A 90-day expiration alert is built into every Phase 1 engagement we run.

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Scenario 8: Brand that switched 3PL providers and silently picked up nexus in 5 new states

The seller

A US-based or foreign DTC brand that, for cost or service reasons, moved fulfilment from one third-party logistics provider to another. The previous 3PL operated from a single warehouse. The new 3PL distributes inventory across its multi-state network. Revenue $1M–$5M.

What they were doing

The seller treated the 3PL switch as an operational decision. They informed their fulfilment team, updated shipping integrations, and went live. No one mapped the new 3PL’s warehouse footprint, and the sales tax engine was not reconfigured.

Where it broke

Inventory in a state creates physical-presence sales tax nexus from day one, regardless of dollar volume. The new 3PL had six warehouses across five states. The seller had nexus in those five states the day inventory arrived — but the tax engine was still configured for the old single-state footprint.

This is the single most common “surprise” finding in our nexus reviews. The seller is told by the 3PL only which warehouse a particular order shipped from, not where their inventory is being held. The inventory is being moved on the 3PL’s logistics logic, not the seller’s compliance logic.

The exposure

• Uncollected sales tax in five new states from the date inventory arrived.
• Trailing nexus rules mean the obligation continues even if the seller switches 3PLs again or pulls inventory out.
• The exposure compounds quickly because direct-channel sales into those states should have been collected on from dollar one — no economic threshold applies once physical nexus is established.

How we’d resolve it

1. Request the 3PL’s warehouse map and the seller’s inventory snapshot by warehouse, with arrival dates.
2. Identify the date physical nexus was established in each new state.
3. Quantify uncollected tax state by state from that date forward.
4. For material exposure, file VDAs. Most states will accept a VDA for the period from inventory arrival to current.
5. Register and configure the tax engine for the new 3PL footprint.
6. Establish a 3PL inventory monitor — quarterly check on warehouse map, with alerts if the 3PL adds or relocates inventory.

If this is you

The 3PL switch is the operational decision. The sales tax map is the compliance decision. They have to happen together.

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If your situation looks like one of these

The scenarios above cover most of what comes through our discovery calls. If yours fits one of them — or is some hybrid we haven’t named — the resolution path is the same in structure:

1. Discovery call — 30 to 45 minutes, no obligation. We need a sense of the seller profile, the channels, the geography, and what you’ve already done.
2. Data request — depending on the scenario, we ask for the Amazon Seller Central inventory report, 24 months of sales data by ship-to state, the 3PL warehouse map, prior W-8BEN-E, prior US filings, and exemption certificates if B2B.
3. Nexus and exposure analysis — typically delivered as a state-by-state memo with the recommended action per state.
4. Phase 1 cleanup — registrations, VDAs where needed, federal protective filings, tax-engine configuration, exemption-certificate library.
5. Phase 2 ongoing — monthly filings, quarterly nexus monitoring, annual federal filings, taxability change alerts, year-end review.

Phase 1 fees typically range from $4,500 to $14,000 depending on complexity, number of states, and historical exposure. Phase 2 ranges from $400 to $1,200 per month depending on state count and channel mix. Every engagement is quoted after the discovery call, not before.

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FAQ

Are these scenarios based on real clients?
No. They are illustrative composites built from the patterns we see most frequently in cross-border seller work. They show the structure of the problem and the structure of the fix, not the facts of any particular engagement. We do not publish identifying details of our clients.

My situation is some combination of these — does that change anything?
Most engagements are a combination. A foreign Amazon FBA seller often also has direct-channel Shopify exposure and a SaaS subscription bolted on. The framework is the same; the workstreams stack.

How long does the cleanup take?
For a typical multi-state cleanup with VDAs, expect 60 to 120 days for the Phase 1 work. Federal protective filings are filed on the federal calendar (5.5 months after fiscal year-end for Form 1120-F).

What does “Voluntary Disclosure Agreement” actually mean?
A VDA is a structured settlement between a seller and a state DOR (or, in some cases, multiple states through the Multistate Tax Commission’s National Nexus Program). The seller comes forward voluntarily, registers, and pays back tax for a limited lookback period — typically three or four years — in exchange for full or partial penalty waiver. It is the standard cure for multi-year unregistered exposure.

Do you work with sellers below $500K in US revenue?
Yes, but we are honest about whether the cost of a managed compliance engagement is justified at that revenue level. For pre-$500K sellers, the Phase 1 work is often the bulk of the value — get the structure right, build the registrations, set up the automation — and Phase 2 can be lean while revenue builds.

Do you handle state income tax as well as sales tax?
Yes. Most foreign-seller engagements span sales tax, state income / franchise tax, federal protective filings, and W-8BEN-E maintenance. They are five separate tax regimes and they get analysed separately for each engagement.

Where can I learn more before contacting you?
The pages below are the foundation:
– What is sales tax nexus
– Economic nexus thresholds by state
– Marketplace facilitator laws by state
– Foreign seller sales tax guide
– SaaS sales tax by state
– FBA sales tax nexus guide

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Last verified: 2026-05-11

This article is for informational purposes only and does not constitute tax advice. The scenarios are illustrative composites, not real client engagements. Consult a licensed tax professional before acting on any of this content.

— Paul le Roux, CA(SA), Sales Tax Compliance USA