Do I Have to Collect Sales Tax on My SaaS in States Where I Have Customers?

Your SaaS business is growing quickly. Customers are signing up across multiple states, and revenue is increasing every month.

Because you sell software online rather than physical products, you assume sales tax probably doesn’t apply.

Unfortunately, that assumption can become very expensive.

Many states now require SaaS companies to collect sales tax once they establish sufficient economic activity within the state. If you overlook those obligations, the unpaid tax, interest, and penalties may not become apparent until a fundraising round, acquisition, or state audit. Understanding when these rules apply helps startups avoid unexpected tax exposure as they scale.

Economic Nexus Changed the Rules

For many years, businesses generally collected sales tax only where they had a physical presence.

That changed after the 2018 US Supreme Court decision in South Dakota v. Wayfair.

Today, many states require businesses to collect sales tax based on economic nexus, meaning a sufficient level of sales activity alone can create a tax obligation.

A company no longer needs an office or employees in a state before sales tax responsibilities may arise.

Sales Thresholds Trigger Collection Requirements

Each state establishes its own economic nexus thresholds. Most states currently require registration after reaching approximately:

• $100,000 in annual sales, or
• A specified number of separate transactions, depending on the jurisdiction.

Some states apply different rules. For example:

• New York generally uses a threshold of $500,000 in sales together with more than 100 transactions.
• An increasing number of states, including Kentucky beginning August 1, 2026, have eliminated the transaction-count requirement and rely primarily on revenue thresholds.

Because these rules differ from state to state, SaaS companies should monitor their sales activity in every jurisdiction where they have customers.

Not Every State Taxes SaaS

Crossing an economic nexus threshold does not automatically mean SaaS is taxable.

Whether software delivered over the internet is subject to sales tax depends on the individual state’s laws.

As of 2026, approximately 25 jurisdictions will tax some form of SaaS during 2026.

Examples include:

• States that generally tax SaaS: Texas, New York, Pennsylvania, Washington, and Massachusetts.
• States that generally do not tax SaaS: California, Florida, and Virginia.

Founders should evaluate both economic nexus and product taxability before determining whether registration is required.

Delayed Compliance Can Become Expensive

Ignoring sales tax obligations does not eliminate them.

If a company should have collected sales tax but failed to do so, many states may review prior years and assess:

• Unpaid sales tax.
• Interest from the original due date.
• Additional penalties.

States commonly examine periods ranging from three to seven years, and penalties may reach approximately 30% of the unpaid tax.

These liabilities often become visible during investor due diligence or acquisition reviews.

Track Revenue by State

Many startups monitor total revenue but pay less attention to where that revenue is generated.

For SaaS businesses, state-by-state reporting is essential.

Regularly reviewing customer revenue by jurisdiction allows founders to identify:

• Which economic nexus thresholds have been exceeded.
• Whether SaaS is taxable in those states.
• Where sales tax registration may already be required.

Monitoring this information throughout the year makes compliance much easier than trying to reconstruct historical data during an audit or financing transaction.

Build Sales Tax Compliance Into Your Growth Plan

As your customer base expands, sales tax should become part of your regular financial review process. Waiting until a financing round or acquisition to evaluate compliance often increases both costs and complexity.

Instead, founders should periodically review sales activity, registration requirements, filing obligations, and potential exposure before problems accumulate.

Building these reviews into normal financial operations helps support smoother fundraising, acquisitions, and long-term growth.

Common Founder Mistakes

• Assuming SaaS is never subject to sales tax: Many states now tax software delivered over the internet, making it important to review each state’s rules rather than relying on a single nationwide assumption.
• Waiting for a state notice before reviewing compliance: Economic nexus obligations generally begin when statutory thresholds are exceeded, not when a tax authority contacts the business.
• Tracking only total revenue instead of state-by-state sales: Without monitoring revenue by jurisdiction, founders may overlook states where registration and tax collection obligations have already begun.
• Ignoring historical exposure before fundraising or an acquisition: Unpaid sales tax, interest, and penalties frequently become due diligence issues that may reduce company value or delay a transaction.

10-Minute SaaS Sales Tax Self Check

• Do I know my revenue by state for both the current and previous year?
• Which states’ economic nexus thresholds have I exceeded?
• Is SaaS taxable in each of those states?
• Am I registered to collect sales tax where required?
• Have I estimated any unpaid tax, interest, or penalty exposure?
• Would my current sales tax compliance withstand investor or acquisition due diligence?

If you cannot answer yes to all of these, you are not ready to face diligence yet. 

Bottom Line

Sales tax for SaaS companies depends on more than simply selling software online. Economic nexus rules, state-specific tax treatment, and customer location all determine when collection obligations arise. Monitoring revenue by state, understanding where SaaS is taxable, and registering before liabilities accumulate helps startups avoid costly surprises during audits, fundraising, and acquisitions.

Unsure Whether Your SaaS Company Has Sales Tax Exposure?

Schedule a free 30-minute call with our team to discuss questions and concerns.

Book here: https://calendly.com/primumlaw/30min