How to register for sales tax in multiple states (and who should handle it)

Registering for sales tax in multiple states means applying for a permit in each state where you have nexus. In the 24 Streamlined Sales Tax (SST) member states, a single application through the SST Registration System covers every member state you select. Every other state requires its own application, on its own portal, with its own requirements and, in some states, its own fee.

That’s the process. For most growing businesses, the harder question is who runs it.

Once you’ve crossed nexus in more than a handful of states, registration stops being a task and becomes a standing obligation. New states as you grow. Permits to maintain. Filing frequencies to track. You have three realistic options: handle it yourself, hand it to your CPA, or bring in a compliance partner built for it.

Who should handle multi-state registration: the three compliance paths compared

The reality of multi-state sales tax compliance is that it’s not a discrete project you can complete and move on. It’s a complex, ongoing business responsibility and a potential liability if you get it wrong.

So, you aren’t just choosing who should manage your registrations and returns. You’re deciding how much risk you can live with and what your safety net is if something goes wrong.

This breakdown compares the three compliance paths available to growing ecommerce businesses: managing compliance internally, handing it off to your CPA, or partnering with a dedicated compliance provider like TaxCloud. Each path has a cost, but only one actually solves the problem.

Internal team: high operational cost, high risk

The rationale behind assigning compliance internally is simple. You already have a finance team, so shouldn’t they take on the work and save you from paying an outside vendor?

The problem is that your finance team is built around financial strategists who have much more valuable work to do. When you go from filing sales tax in one or two states to filing in dozens, compliance becomes an operational bottleneck that brings critical finance workflows to a halt.

Here’s the true cost of managing tax compliance on your own:

• Dozens of diverted hours: Say every state’s registration and filing takes 3 hours. Across 15 states, that’s 45 hours every quarter that your finance team isn’t spending forecasting sales or managing cash flow.
• Missed SST savings: In the 24 SST states, filing costs $0 through a CSP. Handle filings yourself and you give that benefit up: every return costs your team hours instead, and the workload grows with each new state.
• Hidden risk: If your internal team isn’t made up of tax experts, you’re putting your business at risk. A missed nexus threshold, a misclassified product, or a late filing exposes you to costly penalties. And there’s no audit protection when you manage tax in-house, so your business carries 100% of the liability.

CPA: high financial cost, limited sales tax expertise

Turning to your CPA feels like the safest alternative to handling compliance in-house. They know your business and you already have a relationship.

But using your CPA for sales tax management isn’t a sustainable long-term strategy. Here’s why:

• Premium fees: CPAs charge hundreds of dollars per state registration and filing. That’s a massive, recurring financial burden when you have compliance obligations in dozens of states.
• Lack of sales tax expertise: Most CPAs specialize in income tax planning or financial strategy, not sales tax. If your CPA doesn’t closely monitor changes in state sales tax rules or partner with a sales tax provider like TaxCloud, you could be more exposed to audit risk than you realize.
• Limited ownership: CPAs don’t have access to your ecommerce platform. They just file the data you give them. That means your internal team still needs to spend hours pulling transactions, cleaning data, and tracking nexus. Ultimately, the core compliance risk still resides with your business.

TaxCloud: dedicated compliance support, ongoing cost savings

TaxCloud is a U.S. sales tax compliance solution for growing ecommerce businesses that combines powerful automation with real human support so you can stay confident sales tax is handled correctly as your business scales.

Here’s how TaxCloud helps you grow your business without sales tax slowing you down:

• Nexus tracking and multi-state sales tax registration: TaxCloud automatically tracks nexus and registers with both SST and non-SST states when you cross a threshold, so registrations don’t fall behind as you grow.
• Automated tax calculation and filing: TaxCloud integrates with your ecommerce platform, calculates your tax obligations by state, and files returns automatically. Your team doesn’t need to spend hours manually pulling data.
• Plans from $19/month and free filing in 24 SST states: TaxCloud is a CSP for the SST program, so eligible sellers get free registration and filing in 24 SST states. That adds up to significant savings as your business crosses nexus in more states.
• US-based phone and email support: TaxCloud offers real human support from a US-based team of sales tax experts. You’re not left to navigate sales tax alone.
• Audit support add-on available: With the audit support add-on, TaxCloud serves as the primary point of contact for SST state audits. In non-SST states, you get up to 12 amended returns and 8 hours of audit support.

How to register for sales tax in multiple states

To understand why manual compliance fails at scale, you need to see what registering for sales tax in multiple states actually looks like. Here’s the step-by-step process your team has to navigate and the friction points that can trip up growing businesses.

Step 1: Confirm your nexus exposure

Start by determining where you have economic nexus and where you need to collect sales tax. Nexus tracking software is essential for this since every state has different thresholds. States also vary in whether they count marketplace sales towards nexus.

TaxCloud determines where you have nexus automatically based on your historical data. No more guessing. You can jump straight to registration.

Don’t forget to track your physical nexus as well. If you have employees or inventory in a state, you may have nexus there and need to register.

Step 2: Identify SST vs. non-SST states

Whether a state participates in the SST program or not is a key distinction for the registration process.

24 states are SST participants. In these states, eligible remote sellers can register for free through the SST Registration System with a single application. You’ll get a single SST ID that’s used to manage tax permits and returns across all participating states.

The remaining non-SST states each have their own registration applications, online portals, and fees. You have to manage your relationship with each state’s revenue department one-by-one.

Here’s a full breakdown of what you can expect in SST and non-SST states.

Step 3: Gather required tax permit details

In order to register for sales tax permits, you’ll need your business’s EIN, articles of incorporation, and contact information at a minimum.

Non-SST states also have their own state-specific requirements. For example, some states require industry codes or sales projections. Gathering this information ahead of time makes the registration process much smoother.

Step 4: Register for SST states

States that participate in SST use a single application and assign your business a unified SST ID. Fill out the application once, and you can register for sales tax in another SST state with just a few clicks in the future.

Filing in SST states is free if you use a CSP like TaxCloud, which also handles the registration process automatically on your business’s behalf. If you file on your own or with a CPA, you take on the work and cost of every return yourself.

Step 5: Register for non-SST states

Non-SST states require their own application that varies by state, meaning you have to go through individual tax portals for each state. Many of these portals look like they were built in 1999, which adds friction and makes mistakes more likely.

TaxCloud offers flat-rate filing in non-SST states, so you can skip fighting with these portals altogether. All you have to do is share your information with TaxCloud and wait for your registration confirmation.

Step 6: Configure tax collection in your ecommerce platform

Once you’ve registered for sales tax, you need to set up your ecommerce platform to collect tax on sales in each state.

There’s a lot more to this than just clicking an “on” button. Every state has its own tax classifications for different types of products, and you’re responsible for the time-consuming task of assigning each product the correct tax code. If you misclassify a product, you could end up owing back taxes.

TaxCloud provides precise Taxability Information Codes (TICs) for your products so you can be confident you’re collecting tax correctly.

Step 7: Monitor filing frequency by state

Each state will assign your business a filing frequency, which could be monthly or quarterly based on your revenue. It’s up to you to juggle these deadlines. And remember, your ecommerce platform won’t file for you.

Beware that states can change your filing frequency without warning as your sales volume grows. If you’re late to file because your filing frequency changed from quarterly to monthly without you realizing it, you face costly penalties.

TaxCloud files automatically on your business’s behalf, without you having to monitor a spreadsheet of deadlines, so returns go out on time.