# Sales Tax Nexus for SaaS: When to Register and How to Track Thresholds

> When to register for sales tax across US states as a SaaS. Economic nexus thresholds, the registration workflow, and how MoR removes the entire process.
- **Author**: Aarthi Poonia
- **Published**: 2026-06-10
- **Category**: Tax, Compliance, US
- **URL**: https://dodopayments.com/blogs/sales-tax-nexus-saas-when-to-collect

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For SaaS founders, "do I need to collect sales tax in this state" is one of the most operationally annoying questions in US tax compliance. The answer is "it depends on whether you have nexus, and the nexus rules are different in each state." This guide focuses on the practical workflow: how to track when you cross nexus thresholds, how to register, and how to keep filings clean once you do.

For the conceptual "what is nexus" explainer, see the [US sales tax for SaaS guide](https://dodopayments.com/blogs/us-sales-tax-saas). This post is the operational follow-up.

## Recap: the two nexus types

1. **Physical nexus**: you have a physical presence in the state (office, employee, server, inventory)
2. **Economic nexus**: you exceed a sales or transaction threshold in the state without any physical presence

Economic nexus came from the 2018 Supreme Court ruling in South Dakota v. Wayfair. Every state with a sales tax now has economic nexus rules. The thresholds vary by state.

## Economic nexus thresholds by state (selected)

This is a non-exhaustive list of common thresholds as of early 2026. Always verify the current rule with the state's Department of Revenue before registering.

| State | Sales Threshold | Transaction Threshold |
|---|---|---|
| California | $500,000 | No transaction threshold |
| New York | $500,000 | 100 transactions |
| Texas | $500,000 | No transaction threshold |
| Florida | $100,000 | No transaction threshold |
| Illinois | $100,000 | 200 transactions |
| Pennsylvania | $100,000 | No transaction threshold |
| Massachusetts | $100,000 | No transaction threshold |
| Washington | $100,000 | No transaction threshold |
| Georgia | $100,000 | 200 transactions |
| Colorado | $100,000 | No transaction threshold |
| Most other states | $100,000 | Often 200 transactions |

Some patterns:

- The $100,000 / 200 transactions combination is the most common rule (originated with South Dakota itself)
- Larger states tend to use higher thresholds ($500K) and may drop the transaction count
- A few states have unusual thresholds or definitions; always verify

## SaaS taxability is separate from nexus

Crossing nexus does not automatically mean you owe sales tax. SaaS taxability varies by state:

- **Generally taxable**: New York, Pennsylvania, Texas, Washington, Connecticut, Massachusetts, others
- **Generally non-taxable**: California, Florida, Georgia (with exceptions)
- **Taxable for business use only**: some states
- **Taxable for consumer use only**: some states
- **Mixed by feature**: hosted vs downloaded, B2B vs B2C, etc.

A SaaS with $500K in California revenue has nexus there but currently does not owe California sales tax on most SaaS (California treats SaaS as nontaxable). The same $500K in New York triggers nexus AND New York taxes SaaS, so registration and collection are both required.

This is why the operational workflow has two steps: track nexus, then verify taxability per state before registering.

## The tracking workflow

### 1. Track sales and transactions per state monthly

Your billing system or warehouse needs to attribute every transaction to a customer state. This requires capturing customer ship-to or bill-to state at checkout (or, for SaaS, customer billing address state).

Build a monthly dashboard:

| State | Trailing 12-month sales | Trailing 12-month transactions | Threshold | % to threshold |
|---|---|---|---|---|
| TX | $380,000 | 1,200 | $500,000 | 76% |
| FL | $85,000 | 280 | $100,000 | 85% |
| NY | $92,000 | 95 | $500,000 | 18% |

Sort by "% to threshold" descending. The states at the top are the ones to register in soonest.

### 2. Set alerts at the 80% threshold

By the time you hit 100% of a threshold, you are already in nexus and theoretically have to start collecting on the next sale. At 80%, alert the finance team to start the registration process so you are ready before the threshold is crossed.

### 3. Determine taxability before registering

For each state approaching nexus:

- Does the state tax SaaS at all?
- Does the state tax B2B SaaS differently than B2C?
- Are any of your specific features taxable separately (storage, downloads, support)?

If the state does not tax SaaS, you may still need to register (to file a zero return) or you may not, depending on state rules. Confirm with a tax advisor or the state's Department of Revenue.

### 4. Register through the state's sales tax portal

Each state has its own registration portal. Most accept online applications and issue a sales tax license within days to weeks. Common steps:

- Submit business information (EIN, address, NAICS code)
- Pay a registration fee (often $0 to $100)
- Receive your sales tax license/permit
- Set up the filing account in the state's tax portal
- Determine your filing frequency (monthly, quarterly, annual)

For multi-state SaaS, the Streamlined Sales Tax (SST) Registration System covers many states in a single application.

### 5. Configure your billing system to collect

Once registered:

- Add the state's sales tax rate to your billing system for that state's customers
- Decide if it is tax-inclusive or tax-additional pricing
- Test the collection on a sample transaction
- Update your customer invoices to clearly show the tax line

### 6. File and remit on schedule

- Pull the state-specific report from your billing system at the end of each filing period
- File the return through the state portal (the amounts collected, the amounts taxable, the breakdown by tax category if required)
- Remit the collected tax to the state
- Keep clean records for audit purposes

## What goes wrong

### 1. Late discovery of nexus

The most common failure: a SaaS finds out 18 months later that they crossed nexus in 5 states they were not tracking. They owe back tax, plus penalties, plus interest, on sales they did not collect tax on. Cleanup cost is often 5x to 10x what proactive compliance would have cost.

### 2. Inconsistent customer location data

Some billing systems do not require complete billing addresses. If you do not know the customer's state, you cannot attribute their transactions to a state, and your nexus tracking is broken.

### 3. Treating SaaS as universally non-taxable

Founders sometimes assume SaaS is not taxed because California does not tax it. The opposite is true: most US states tax SaaS in some form. Defaulting to "we do not collect" is risky.

### 4. Mixing nexus dates and effective dates

Some states require you to register effective the date you crossed nexus (potentially weeks or months in the past). Others let you register prospectively. Mixing these up creates back-tax exposure.

### 5. Forgetting marketplace facilitator rules

If you sell through a marketplace (Apple App Store, Shopify App Store, etc.), the marketplace may already be collecting and remitting sales tax on your behalf. Double-collecting is a refund headache.

> The most expensive sales tax mistake we see is not the rate, it is the lag. By the time founders realize they crossed nexus in 12 states, the cleanup bill is in five or six figures. Proactive tracking is dramatically cheaper than reactive cleanup.
>
> \- Ayush Agarwal, Co-founder & CPTO at Dodo Payments

## How a merchant of record changes the picture

The entire workflow above (track, register, configure, file, remit) is overhead a SaaS founder has to maintain themselves. For a US-domestic SaaS, this is annoying but manageable. For a global SaaS that adds VAT, GST, and country-specific digital services taxes on top, it is a major operational burden.

A [merchant of record](https://dodopayments.com/blogs/what-is-a-merchant-of-record) absorbs the full sales tax stack as the legal seller. The MoR registers in the relevant states, collects tax on the transactions, files returns, and remits to the states. The underlying SaaS supplier does not register, configure, file, or remit US sales tax.

For Dodo Payments specifically, this coverage extends across [190+ tax jurisdictions globally](https://docs.dodopayments.com/features/tax), including US states, EU VAT, UK VAT, GST regimes, and country-specific digital services taxes. The trade-off is the MoR fee (4% + 40c on the Standard Plan, plus documented add-ons). For a SaaS that would otherwise spend $20K to $100K per year on tax compliance services, the MoR economics often net out cheaper.

## When to go MoR vs DIY

| Situation | Recommendation |
|---|---|
| US-only SaaS, finance team in place | DIY with a tax tool (Stripe Tax, Avalara, TaxJar) |
| US-only SaaS, founder-led | DIY initially, MoR once nexus spreads to 10+ states |
| Global SaaS, any size | MoR strongly preferred |
| Enterprise SaaS with custom contracts | DIY with a dedicated tax advisor |

## FAQ

### What is sales tax nexus?

Nexus is a legal connection between your business and a state that obligates you to collect and remit sales tax there. Physical nexus comes from physical presence (office, employee, server). Economic nexus comes from exceeding sales or transaction thresholds in the state.

### What is the typical economic nexus threshold?

$100,000 in sales or 200 transactions in the trailing 12 months is the most common pattern, originating with South Dakota's law. Larger states use higher sales thresholds ($500K is common). Always verify the current rule with the state.

### Does crossing nexus mean I owe sales tax?

Not always. Nexus is the obligation to register and potentially collect, but the actual collection depends on whether your product is taxable in that state. SaaS is taxable in some states (NY, PA, TX, WA) and nontaxable in others (CA, FL). You may need to register and file zero returns even if you do not owe tax.

### How do I track nexus across states?

Build a monthly dashboard showing trailing 12-month sales and transactions per state. Set alerts at the 80% threshold for each state. Investigate taxability before registering. This requires capturing customer billing state on every transaction.

### Can a merchant of record handle US sales tax for me?

Yes. An MoR is the legal seller and registers, collects, files, and remits US sales tax on transactions it processes. The underlying supplier (you) does not interact with state tax portals. This is one of the largest operational benefits of the MoR model for SaaS.

## Conclusion

Sales tax nexus tracking is an unglamorous but high-stakes part of SaaS operations. The cost of staying ahead of it is far lower than the cost of cleaning up after the fact. Build the tracking dashboard, set the alerts, and engage state by state as thresholds approach.

If you would rather not own this workflow at all, a merchant of record like [Dodo Payments](https://dodopayments.com) absorbs sales tax compliance across the US (and 190+ jurisdictions globally) as the legal seller. See [pricing](https://dodopayments.com/pricing).
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