Sales Tax for SaaS Companies: Nexus, Taxability and What Changes in 2027

Whether you charge sales tax on your SaaS comes down to two separate questions: do you have nexus in a state, and does that state tax SaaS? You collect only where both answers are yes.

The second answer is about to change in the largest US market. California begins taxing SaaS on 1 January 2027, ending more than three decades of exemption, so a position that looked settled in 2026 needs rechecking.

TL;DR

• Two tests: nexus (physical presence, or $100,000 of economic activity since Wayfair in 2018) and taxability (around half the states tax SaaS, often differently for business and consumer buyers).
• Getting compliant: register before you collect, then file on the state's assigned schedule, including zero returns in quiet quarters.
• California: SB 122 brings prewritten software and SaaS into the tax base from 1 January 2027. Custom software stays exempt.
• Foreign sellers: being outside the US is not an exemption. Economic nexus applies to where your customers are.
• What goes wrong: thresholds crossed unnoticed, and registrations opened but never closed.

Why SaaS Sales Tax Is Harder Than It Looks

Sales tax is charged by states rather than by the federal government, so there are 46 separate state and DC systems to satisfy, with no national registration covering them.

Two independent tests decide whether you collect in any given state:

• Nexus. Do you have enough connection to that state for it to require you to collect?
• Taxability. Is the thing you sell taxable under that state's rules?

Both have to be true. Having nexus in a state that does not tax SaaS creates a registration question but no collection obligation, and selling taxable software into a state where you have no nexus creates neither.

Software makes the second test unusually messy. States wrote their sales tax codes around tangible goods, then had to decide whether access to remotely hosted software counts, and they reached different answers.

Step One: Where Do You Have Nexus?

Nexus comes in two forms, and you need to test for both. Physical presence was the only trigger until 2018, and it still applies.

Physical nexus is usually created by:

• An office, server or other property in the state
• Employees or contractors working there, including remote staff
• Inventory stored in the state
• Attending trade shows or sending staff to sell, in some states

Economic Nexus Changed the Rules in 2018

You can owe sales tax in a state you have never set foot in. In South Dakota v. Wayfair (June 2018), the Supreme Court held that economic activity alone is enough for a state to require an out-of-state seller to collect.

Every state with a sales tax now has an economic nexus threshold. The common standard is $100,000 of sales into the state over a twelve-month period, though several large states set theirs higher.

Some states also count transactions, typically 200 in a year. In most of them crossing either trigger creates nexus, though a few require both to be met.

That transaction test is being repealed in state after state because it caught small sellers of low-priced products, so check the current rule, not a chart from a few years ago.

How the measurement period is defined varies too, and it is easy to get wrong:

• Some states look at the current or previous calendar year
• Others use a rolling twelve-month window that moves with every sale
• A few measure against their own fiscal year

Whether the threshold counts gross sales, retail sales or only taxable sales also differs. A business under the limit on taxable sales can be over it on gross, which is why the safe approach is to track gross revenue by state and investigate as you approach any threshold.

Five States Have No Statewide Sales Tax

New Hampshire, Oregon, Montana, Alaska and Delaware impose no statewide sales tax, so there is nothing to register for at state level.

Alaska is the exception that matters. It has no state sales tax but permits local jurisdictions to levy their own, and many do, with their own economic nexus rules administered collectively rather than borough by borough.

Two practical points follow for sellers into these five states:

• There is no state registration to make, so no filing calendar is created
• Sales into them can still count toward other states' gross-sales thresholds, depending on how each state defines its measure

So a no-sales-tax state is not a no-consequence state. It removes an obligation locally while still contributing to the numbers that create obligations elsewhere.

Step Two: Is Your SaaS Taxable in That State?

Nexus tells you a state can require collection. Taxability tells you whether there is anything to collect.

Roughly half of US states tax SaaS in some form, and that list has grown steadily. States generally land in one of three positions:

That third category is the easiest to miss. Some states tax SaaS sold for personal use while exempting or reducing it for business use, which means your own customer mix changes your answer within a single state.

How a state classifies the product also matters. A state may treat SaaS as tangible personal property, as a data processing service, or as a distinct digital product, and the classification determines both the rate and which exemptions apply.

That classification is rarely something you choose. It follows from how the state's statute is written and how its revenue department has interpreted it, so two products that look identical commercially can be treated differently.

Bundled Subscriptions Can Pull Everything Into the Tax Base

Bundling can drag untaxed items into the tax base. Where a subscription includes software alongside other elements, some states tax the whole bundle if the taxable element is not separately stated:

• Implementation and onboarding fees
• Support and success plans
• Training and professional services
• Hardware or devices shipped with the subscription

Separating line items on invoices is therefore a tax decision as much as a billing one. Decide the invoice structure when you design pricing, because unpicking it during an audit is considerably harder.

The Five Inputs That Decide Your Position

The answer is specific to your business, and five pieces of information produce it.

• Revenue by state. Twelve months of sales, split by the customer's location, is the input everything else runs on
• Physical footprint. Offices, remote employees, contractors and any property, by state
• Customer mix. Business versus consumer, since several states treat the two differently
• Product classification. How your offering is characterized, since a state may treat it as software, a service or a digital product
• Sales channel. Direct sales against anything sold through a marketplace or reseller

With those five, you can test each state in turn. Nexus first, taxability second, and only where both land does a registration follow.

Doing this once is not enough. Thresholds are rolling and your own footprint moves every time you hire remotely or win a customer in a new state, so put it on a quarterly review cycle.

Where the answer is genuinely unclear, states publish guidance and many will issue a written ruling on a specific set of facts. That takes longer than reading a vendor chart, and it is what you want on record if a material amount of revenue turns on the answer.

California Changes the Picture in January 2027

California enacted SB 122 in June 2026, bringing digital prewritten software including SaaS into the sales and use tax base from 1 January 2027.

The state had exempted remotely accessed software for more than three decades, so this is the largest single change in US SaaS taxability in a generation.

California projects roughly $900 million in general fund revenue and $1.1 billion in local sales tax annually. A change of that size will be administered closely.

Act before the date, not after: a SaaS business with California customers that has never registered there now has a registration, rate and invoicing change to make before its first January 2027 invoice goes out.

The legislation also introduces sourcing rules and, in some circumstances, shifts responsibility for remitting the tax from the seller to the purchaser on large aggregate transactions. If California is a material market for you, get professional review before you touch the billing settings.

Three practical consequences follow for a business with California customers:

• A California registration where none existed, assuming you meet the state's $500,000 economic nexus threshold
• A rate change on every California invoice, combining the state rate with local district rates by customer address
• A commercial conversation, since the cost lands on customers who were not paying it in 2026

The pricing question is the one that needs lead time. Whether you absorb the tax or pass it on is a decision to make before renewal conversations start, not in January.

Register First, Then Collect: The Order Matters

Crossing a threshold does not start collection on its own. You register with the state, then charge tax, then file returns on the schedule that state assigns you.

• Register with the state tax authority once you have nexus, and before you collect anything
• Configure your billing system to apply the right rate to the right customers
• Collect the tax as part of the subscription charge
• File and remit on the state's schedule, which may be monthly, quarterly or annually

Collecting tax without being registered is its own problem, so the order matters. Tax collected from customers is held on their behalf, and a business that charges it without a registration has money it has no mechanism to remit.

Filing frequency is assigned rather than chosen, and it usually scales with volume:

• Higher-volume filers are generally put on monthly returns
• Smaller filers may be quarterly or annual
• Several states require a zero return even in periods where you collected nothing

A quiet quarter is therefore not a quarter off, and missing a zero return produces the same delinquency notice as missing one with tax on it.

Rates are the other moving part. Sales tax is rarely a single state rate, because counties, cities and special districts add their own.

Two customers in the same state can therefore owe different combined rates, because the rate follows their address rather than the state line. That has three practical consequences:

• You need customer addresses accurate enough to resolve to a jurisdiction, not just a country
• Rate tables go stale, since local rates change on their own schedules
• A single wrong address produces a wrong rate on every invoice until it is corrected

Billing systems generally handle this through rate lookup, but only if the addresses you hold are accurate and complete enough to resolve to a jurisdiction.

Selling SaaS into the US from Outside It

Being a foreign company is not an exemption. Economic nexus looks at where your customers are, not where you are incorporated or where your team sits.

A software business in Bengaluru or London with $100,000 of sales into a US state can have a collection obligation there, with no US entity, no US staff and no US office.

Two points in particular are worth knowing:

• No treaty relief. Income tax treaties can reduce or remove US income tax exposure, and they do nothing for sales tax, which is a state-level transaction tax outside their scope.
• Registration usually needs a US tax ID. Most states want an EIN on the application, which puts an IRS step ahead of the state one.

Marketplace facilitator rules can change the answer if you sell through an app store or reseller. Those laws shift the collection obligation to the marketplace for sales made through it, though direct sales you make yourself stay yours.

That split is worth mapping early, because most software businesses end up with both. Revenue arriving through a marketplace may already be handled, while the same product sold direct from your own site is entirely your obligation, and the two can cross a threshold together.

Payment processors are not marketplaces for this purpose. Taking card payments through a gateway does not move the collection obligation anywhere, and a tax feature offered by a billing provider calculates the tax; it does not assume liability for it.

Four Mistakes That Create Back Taxes

Each of these creates an exposure that compounds quietly, because sales tax you did not charge a customer still has to be paid.

Nobody Watches the Threshold Until It Is Crossed

Economic nexus is measured on a rolling basis, and it does not announce itself. A business can cross $100,000 in a state in March and not discover it in October.

The exposure is retrospective. Tax that should have been charged from the crossing date is owed whether or not you collected it, and by then the customers who should have paid it have already been invoiced without it.

Track sales by state from the point US revenue becomes material, not from the point someone asks about it. Two numbers are worth having monthly:

• Trailing twelve-month gross sales into each state
• How close each state sits to its own threshold

B2B Sales Are Taxable in Most States That Tax SaaS

B2B does not mean exempt. Some states do treat business use differently, but that is a specific rule in specific states rather than a general principle, and in most taxing states a sale to a business is taxable like any other.

Where an exemption genuinely applies, it usually depends on collecting and keeping a valid exemption certificate from the customer. No certificate means no exemption on audit, regardless of what the customer's status actually was.

Certificates also expire and vary by state, so a document collected once at the start of a relationship may not cover a sale three years later. Keep them in one place with their expiry dates, and re-request when a state's validity period lapses.

Every Registration Adds a Filing Calendar You Cannot Quietly Drop

Registration creates an ongoing filing obligation that outlives the revenue which triggered it. Returns keep falling due, in several states even for periods with no sales at all.

A business that registers in fifteen states has taken on fifteen filing calendars. Closing a registration properly when you genuinely no longer have nexus is a deliberate step, and going quiet instead produces delinquency notices.

Registering early in a state you have not yet reached the threshold in carries the same cost. The obligation starts when the registration does, so register voluntarily only when you have a reason to, not out of caution.

Your Billing System Still Has Its Launch-Day Tax Settings

Subscription billing tools apply whatever tax logic they are configured with. A default set at launch, before you had customers across the country, does not update itself as your footprint changes.

An annual audit of the configuration is usually enough. Three things are worth checking:

• Which states are switched on for collection, against where you actually have nexus today
• Which product codes map to which tax category, since a miscoded product applies the wrong treatment everywhere
• When the rate tables were last refreshed, because local rates move on their own schedules

Worth checking: rates change, states change their SaaS treatment, and California's 2027 change will need a configuration update rather than an automatic one.

How FinStackk Helps With SaaS Sales Tax

Sales tax compliance turns on thresholds being watched and registrations being closed. Our SalesTaxx module automates sales tax compliance, and Fin-Tax tracks the federal, state, county and city filing deadlines that follow from each registration.

If you sell SaaS into the US from outside it, or you are working out what California's 2027 change means for your billing, book a call and we will work through where your obligations already sit.

Frequently Asked Questions

Do you charge sales tax on SaaS?

It depends on the state. Roughly half of US states tax SaaS in some form, and you only charge tax where you have nexus and the product is taxable. Both conditions have to be met.

California is the significant change ahead: it has exempted SaaS for over three decades and begins taxing prewritten software and SaaS on 1 January 2027 under SB 122.

What is the sales tax nexus threshold for SaaS?

The most common economic nexus threshold is $100,000 of sales into a state over twelve months, adopted by the large majority of states after the 2018 Wayfair decision. Some of the largest markets, including California, New York and Texas, use $500,000 instead.

Some states also count transactions, often at 200 per year, though that test is being repealed in a growing number of states. Physical presence creates nexus independently of any dollar threshold.

Do foreign SaaS companies have to collect US sales tax?

Yes, potentially. Economic nexus depends on where your customers are rather than where your business is established, so a company with no US entity or staff can still cross a state threshold and owe collection there.

Income tax treaties do not help, because sales tax is a state-level transaction tax outside their scope. Registration generally requires a US tax identification number, so an EIN is usually the first step.

Related reading

Once your SaaS business has nexus, the next step is registration and filing, covered in our sales and use tax compliance guide.