SaaS Sales Tax Compliance: A 6-Step Framework for 2025

You’ve already started thinking about sales tax compliance. Maybe you’ve registered in a few states. Maybe you’ve even bought tax automation software.

But if you’re like most SaaS companies we work with, you’re still unsure: Are we doing this right? What’s missing? And what happens if we’ve overlooked something important?

The truth is, many SaaS finance leaders, especially CFOs, Controllers, and Heads of Finance, are unintentionally non-compliant. Not because they’ve ignored the rules, but because the rules are confusing, tax software is limited, and guidance is often vague or incomplete.

This guide outlines the 6-step framework we use with SaaS and technology clients who want to get compliant and stay that way, without wasting time or money on unnecessary tools or reactive clean-up. Whether you’re just beginning or already knee-deep in filings, this article will help you move forward with clarity.

Why trust us?
At Miles Consulting Group, we’ve been helping SaaS companies with sales tax for over 23 years. Our team includes professionals with backgrounds at Big Four firms, major tech companies, and state tax agencies. We know the roadblocks because we see them every day and we know how to help you navigate around them.

Step 1: Start with a Nexus Review

Not sure where you owe sales tax? Start here. Most SaaS businesses trigger sales tax obligations (aka “nexus”) in more states than they realize, but the only way to know for sure is with a thorough nexus and taxability review.

Neglecting this step could mean you owe back taxes to states dating back years, resulting in costly financial penalties. Most states place no limit on how far back they can go if you never registered and they take enforcement seriously.

If you’re heading toward a merger or acquisition, this kind of exposure can create significant issues around successor liability.

At Miles Consulting Group, we help SaaS and tech companies conduct a 25–50 state nexus assessment (depending upon their needs) to identify where they’ve triggered sales tax obligations. We look at:

Where your employees are based
Where your customers are located
What SaaS products and related services you offer
How long you’ve been operating in each state

We also identify when your obligations began, whether your services are taxable, and how to fix any retroactive exposure.

A proper nexus review helps you:

Understand where you have economic or physical nexus
Quantify your risk
Avoid registering too early or too late

Completing this step first gives you clarity on what to do next, including whether (and how) to invest in sales tax software.

A proper nexus review is the foundation for every other sales tax decision.

Step 2: Map Your Customer Footprint by State

Once you’ve identified the types of nexus that apply to your business, it’s time to audit where your customers are located.

This can feel straightforward, but it’s often more complicated than expected.

For example:

Are your “customers” the company paying for the subscription, or the end users?
How do you handle usage across multiple states?
What if you’re selling SaaS through a marketplace platform?

Customer location has a direct impact on where you may create nexus and need to collect tax. That means mapping out your customer base by both billing and usage, is a critical early step.

If it appears that you do have tax liabilities in certain states, we generally recommend engaging in Voluntary Disclosure Agreements (VDAs). These are confidential programs that allow companies to proactively disclose past-due tax obligations to a state, usually in exchange for penalty relief and limited lookback periods.

In most cases, engaging in a VDA will result in any penalties being reduced, or sometimes fully waived. You’ll be less likely to face legal consequences and can operate without the fear of surprise audits.

Once you know your nexus and estimated tax liabilities, you’ll need to remediate any taxes owed. You can register with the states you’re trading in at the same time as making remediation, which means you’ll then be able to collect sales tax and file returns in those states. From that point forward, you can be confident you’re operating in a compliant manner.

VDAs cannot be managed by software and require expert navigation to avoid non-compliance. If you’re not sure where to start, we discuss this along with other key early compliance steps in this article.

A VDA is often the fastest and safest way to resolve past exposure before registration.

Need clarity on where you might have triggered nexus? We offer a complimentary nexus consultation review to help you assess exposure and avoid downstream issues.

BOOK YOUR REVIEW HERE

Step 3: Register in the States Where Nexus Applies

Once a SaaS or technology company has established nexus in a state, it is legally required to register for a sales tax permit before collecting any tax. This must be done with each state’s tax authority by completing their online registration process. These permits may be called a sales tax permit, seller’s permit, or sales tax license, depending on the jurisdiction.

Some states charge a small fee for registration, while others offer it for free. Once approved, you’ll receive a unique sales tax ID number for that state, which legally authorizes you to begin collecting and remitting tax.

Important: Registration cannot be completed by software tools alone. Each state’s registration process must be handled individually, and the questions handled thoughtfully. For this reason, we recommend working with a specialist tax consultant who can manage this on your behalf. This not only speeds up the process but helps avoid costly errors—especially for businesses registering in multiple states for the first time.

Registering too early, too late, or in the wrong states can create downstream compliance burdens. Follow your nexus findings carefully.

Step 4: Collect the Tax

Once you’ve registered in the states where you’ve triggered nexus, it’s time to begin collecting sales tax.

This means updating your billing systems, invoicing software, and payment platforms to apply the correct tax rates based on where your products are shipped. Because tax rates and rules vary widely across jurisdictions and exemptions may apply, doing this manually can be difficult at scale.

Automated sales tax software like Avalara, Anrok, or TaxJar can help manage this complexity. These tools, known as “sales tax engines” integrate with your invoicing systems to apply the correct tax rates and generate detailed reports.

But automation alone isn’t enough. Incorrect product or service coding can result in faulty calculations across multiple states and software can’t always catch those errors. That’s why we advise working with a specialist sales tax consultant who can:

Validate tax coding accuracy
Monitor how taxes are applied across different states
Spot filing mistakes early before they become costly

Even the best software is only as good as the data and configuration behind it. Human oversight is critical.

If you’re invoicing at scale, this step is where errors compound quickly, so getting this right will save time, rework, and compliance risk down the line.

Need clarity on where you might have triggered nexus?
We offer a complimentary nexus consultation review to help you assess exposure and avoid downstream issues.

BOOK YOUR REVIEW HERE

Step 5: Use Software Strategically, But Not Too Soon

Hands down the biggest problem we see is when clients invest in automated sales tax software too soon. It is almost always the case that SaaS and technology companies understandably view software as the complete solution to all their tax problems and so invest heavily in software tools they believe will make their tax situation simpler to manage.

There is no doubt that software solutions have huge benefits, but a problem we often come across at Miles Consulting is that the software is not always implemented effectively, which means you can run into issues further down the line.

Often when clients come to us they have already invested in software packages, but these are not always the best fit for their needs, meaning they are often paying for services which are not appropriate for their specific circumstances or, they have huge gaps in their compliance process that the software cannot fill.

That doesn’t mean sales tax software is bad, it’s just often used too soon or not set up correctly.

Once the groundwork is done, platforms like Avalara, Anrok, and TaxJar can streamline your calculations and filings, but they still require correct setup, configuration, and ongoing oversight.

Software is a tool, not a solution. If used at the wrong time or in the wrong way, it can introduce more risk than it removes.

We help clients:

Select the right tool (if one is needed)
Implement it properly
Monitor what automation misses

If you’ve already bought software and aren’t confident in how it’s working, we’re happy to review your current setup.

Step 6: Partner with a Specialist Tax Consultant

While software plays an important role, it cannot fully replace the judgment, insight, and experience of a dedicated tax professional.

At Miles Consulting Group, we specialize in helping SaaS and technology companies confidently manage their multi-state sales tax obligations, not just once, but on an ongoing basis.

Why choose us?

Over 23 years of experience focused exclusively on sales tax compliance
Team includes former Big Four advisors, ex-state auditors, and SaaS specialists
Trusted by scaling and post-acquisition tech companies nationwide

We don’t just advise. We actively:

Monitor your nexus as your business grows
Validate your system setups and software configuration
Utilize technology along with human intervention to properly file returns – monthly, quarterly or annually, as the states require.
File your returns through state portals, if needed

Whether it’s economic thresholds, product taxability, or state-specific quirks, we help you stay compliant with clarity and confidence.

The right tax partner isn’t just a fallback. It’s your strongest insurance against audit risk and future rework.

What If You’ve Already Started?

If you’ve already registered in some states, or bought software but aren’t sure if you’re fully compliant, you’re not alone.

We often step in at this exact moment, helping SaaS teams fix gaps, simplify workflows, and avoid bigger problems later.

If you’d like a second opinion, we’re happy to offer a review.

Sales tax compliance for SaaS doesn’t need to be a guessing game.

Whether you’re prepping for due diligence, scaling to new states, or revisiting what your software missed, the right framework can save you months of rework and thousands in exposure.

We’ve helped SaaS companies at every stage from early growth to post-acquisition build a compliance plan that actually holds up.