How to choose an SST Certified Service Provider

You choose an SST Certified Service Provider by working six criteria rather than a ranking: whether you qualify for free CSP services state by state, integration fit, the pricing model, the support model, audit and certificate handling, and company scope. Six providers are certified and five currently offer free services. The criteria point at different providers for different businesses, and no provider wins all six.

If you’re already filing somewhere, through a provider or a spreadsheet, the question isn’t what a Certified Service Provider is. It’s which one you move to. A CSP is an agent certified under the Streamlined Sales and Use Tax Agreement to perform a seller’s sales and use tax functions, other than the seller’s obligation to remit tax on its own purchases, and member states compensate it for that work. The states fund the same certified scope whichever provider you pick, so everything that decides the choice sits outside that scope.

The short version

Certification is a floor, not a differentiator. All six systems are certified and member states provide liability relief for incorrect calculation on that basis. That tells you nothing about which one to hire, so it isn’t where your evaluation starts.
Your own footprint decides more than the vendor does. Free CSP services apply per state, in the full member states where you qualify, and the non-member states are usually the larger bill. You’ll get further starting from your own state list than from any vendor’s feature list.
Three of six publish no pricing at all: Sovos, AccurateTax, and Avior, checked 2026-08-19. Cost isn’t a filter you can apply across the whole field.

Which criteria actually decide the choice?

1. Free-service coverage and qualification fit

This is the largest cost variable, and it turns on how you operate rather than which vendor you hire. You qualify as a CSP-compensated seller one state at a time, measured against all five criteria in the CSP Operating Contract, and distributed inventory or a remote employee can fail the Property and Payroll gates in the states you sell into most. Test it by running the CSP-compensated seller test state by state, and plan on the 23 full member states where you qualify, because Tennessee’s associate status is unresolved. If you’re running this across several clients, treat it as a per-client procedure, because the answer follows each client’s own Property, Payroll, and places of business.

Five of six offer free services. Exactor is the exception, listed by the Governing Board as certified and not currently offering free services under the program. Across the other five the program sets the scope, so this criterion sorts buyers rather than providers. See what a Certified Service Provider is.

2. Integration and technical fit

Two questions, and the second gets skipped. Does the provider connect to the system your revenue runs through, and does it calculate the tax or only receive it? Test it by naming your whole stack, billing tool included, then asking for each connector by name, the tier it sits on, and who calculates at checkout.

Avalara publishes 1,400 plus partner integrations, naming NetSuite, SAP, Oracle, Microsoft Dynamics, Shopify, and Stripe, though its pricing page attaches all integrations to the unpriced Custom tier.
Avior lists eight platforms including Oracle NetSuite, Odoo, and QuickBooks, and publishes no Shopify, BigCommerce, marketplace, or billing connector.
Sovos publishes adaptors for SAP, Oracle NetSuite, Microsoft Dynamics, Magento, QuickBooks Online, and Shopify, and lists no BigCommerce, WooCommerce, marketplace, or Stripe connector.
TaxCloud lists BigCommerce, Shopify, Stripe, WooCommerce, Chargebee, Odoo, and QuickBooks, publishes no SAP or Microsoft Dynamics, and on Shopify and Stripe those platforms calculate at checkout.
AccurateTax lists nine carts and an XML based API, and publishes no ERP or billing connector.
Exactor publishes nothing, checked 2026-08-19.

The same connector detail sits in the integration column of all six providers side by side.

3. Pricing model, including the states the program does not cover

Ask for the unit, not the headline number. Per-state pricing punishes a wide, thin footprint. Per-order pricing punishes volume. Everyone prices the non-member states separately, and for most multi-state sellers that’s where the majority of the bill lands. Test it by making every vendor state the unit, quote at your current volume and at double it, and price the non-member states.

Avalara publishes a named SST tier at $69 per state per month for sellers under $50M in annual revenue, checked 2026-08-19, and says standard pricing and per-return fees apply outside the program without publishing that figure. AccurateTax publishes the shape and not the number, keyed to order count, and files across state, county, and home rule city jurisdictions, as does Avior, which publishes no price either. TaxCloud publishes both of its plans, a subscription by order volume and a filing plan by return count, from $199 and $399 a year respectively, and you buy both. Its filing plan is priced outside SST scope. It also publishes a $39 per month filing floor on monthly billing, and includes SST on all plans with no tier condition. Sovos publishes nothing and treats coverage outside certified states as a separate purchase. See what each certified provider charges.

4. Support model and buying path

Which channels are included rather than sold, whether anyone commits to a response time in writing, and whether you can evaluate before a sales call. Test it by asking which channels sit on the tier you’re actually buying, and for the response-time target and the implementation plan.

Avalara publishes response-time targets, checked 2026-08-19: 24 hours on the included tier in weekday hours, with phone and live chat on paid tiers whose prices are not published.
TaxCloud includes phone and email on both tiers with a US based team, commits to no response time, and estimates onboarding at a few days, or several weeks or months where custom integrations or an ERP are involved.
Sovos names a dedicated Sovos tax professional as your primary contact, publishes no hours or targets, and offers no trial or self-serve signup.
AccurateTax offers email support around the clock, phone in business hours, and quotes by email.
Avior publishes no hours, target, escalation path, or service level agreement anywhere checked 2026-08-19.
Exactor publishes no support terms, and no route in beyond an Intuit email address.

5. Audit, notice, and exemption certificate handling

What happens when a state pushes back, and whether a provider manages your exemption certificates or merely records them. Notice and audit response sits on the Governing Board’s certified free services list. Test it by asking who the named contact is in a state audit, and whether certificate verification and renewal tracking are work the provider performs.

Certification is the floor, and the one dimension where all six stand together: member states provide liability relief for incorrect calculation based on the certified system, Exactor’s included. Above that floor, in a Model 1 audit Sovos says it “serves as the first point-of-contact, not the seller.” It also says liability relief isn’t absolute, and gives a seller who maps an item wrong as the example. Avalara records notice management and audit support on its Governing Board listing and names Exemption Certificate Management in its covered SST services. Avior’s listing carries audit support and no notice response. AccurateTax describes neither on any page checked 2026-08-19, including its own listing. TaxCloud states its platform stores and applies certificate details without automated verification or renewal tracking and doesn’t store the document, and its pricing page lists audit support as both a $99 per month add-on and a free SST service.

6. Company scope and stability

How large the vendor is, and how much of its business your use case represents. A narrow vendor concentrates on your problem. A broad one covers obligations you may pick up later. Test it by taking the certification date from the Governing Board listing rather than from the vendor.

Avalara reports 41,000 plus customers and has been privately held since Vista Equity Partners took it off the NYSE in 2022.
Sovos reports more than 2,600 employees, and its customer count depends on the source: its own site puts it above 100,000 and its Governing Board listing above 7,000, both primary.
TaxCloud covers the United States plus Canada, publishes no VAT support, and sells into a single market.
AccurateTax and Avior publish no scale figures, and Avior’s sales tax line is one of five alongside tobacco, fuel, alcohol, and scan data, certified effective January 1, 2024.
Exactor has no independent presence and is described by the Board as a subsidiary of Intuit.

Which provider fits which buyer?

Four situations, worked on the published record.

Enterprise on SAP or Oracle with a global footprint

Sovos and Avalara. Both publish ERP-first catalogs naming SAP, Oracle NetSuite, and Microsoft Dynamics, and both sell scope beyond US sales tax, Avalara across 190 plus countries and Sovos across VAT, e-invoicing, and information reporting. It points away from the smaller providers: TaxCloud publishes no SAP or Microsoft Dynamics connector and no VAT support, AccurateTax no ERP connector at all, and Avior names Oracle NetSuite but no SAP or Dynamics. Verify: Avalara’s published tiers stop at $50M in revenue, so above that you’re quoting rather than comparing, and your connector may sit on the unpriced Custom tier. Sovos Model 1 requires you to use it for both calculation and reporting, so you can’t keep your own engine, and it doesn’t publish a price.

Mid-market multi-state US ecommerce or SaaS on mainstream carts

TaxCloud.

Its published connector list (BigCommerce, WooCommerce, Chargebee, Shopify, Stripe) matches this stack more closely than the ERP-first catalogs do, both of its plans are published in full so you can model the cost before you take a call, and phone and email are included on both tiers against Avalara’s included tier of online case submission, with phone and chat on unpriced paid tiers. That compares what each provider includes, not how well either one performs.

Avalara is the alternative, and it’s the right one if your obligations run past US sales tax. It covers 190-plus countries and eight tax types beyond sales and use, and its named SST tier at $69 per state per month is straightforward to model under $50M in annual revenue, checked 2026-08-19.

Verify: TaxCloud’s subscription and filing plans are priced on separate ladders and you need both, so get the combined figure at your own order and return volumes in writing. Confirm who calculates at checkout, because on Shopify and Stripe those platforms do. Test support against references, since there’s no published response time. Avalara’s per state per month unit charges the same in your smallest state as in your largest, and it’s worth a third quote from AccurateTax at high volume on one of its nine carts.

Small remote seller just crossing thresholds in a handful of states

Genuinely open, and your footprint decides it rather than the vendor. With no warehouses and no remote staff, you’re the profile most likely to meet all five criteria in most states, so free CSP services cover a large share of the bill. Count how many of your handful are full member states. If most are not, the program isn’t the deciding factor and this is an ordinary software decision.

At four or five states, Avalara’s published tier is easy to model and AccurateTax’s per-order unit can suit a low state count with real volume. TaxCloud publishes a five-state floor for fit, so it enters at five, and its two plans are priced on units of their own, by order volume and by return count. Each of the three publishes something a small team can act on without a procurement process, while Sovos is scoped to enterprises with an in-house tax function and has no self-serve path, and Avior publishes neither price nor support commitment. Verify: the status isn’t permanent, and it gets re-tested on a later period than the 12 months that qualified you, so a yes at registration isn’t a yes you keep. Re-run the CSP-compensated seller test whenever you add a warehouse, a 3PL location, or a remote employee, because you lose it in that state rather than everywhere at once.

Business with heavy wholesale and high exemption certificate volume

Avalara first on the published record, then Sovos and AccurateTax as quoted add-ons. Avalara names Exemption Certificate Management with data capture and processing inside its covered SST services, and its Governing Board listing records certificate management among the free services for qualifying sellers. Sovos sells CertManager and AccurateTax sells certificate management, both separate purchases rather than bundled, which keeps them viable and changes the cost conversation. Avior lists exemption certificates on its listing, with no price attached.

It points away from TaxCloud, and its own materials are the reason. Its exemption certificate page says the platform “doesn’t provide automated verification or renewal tracking.” The same page states it doesn’t capture or store the certificate document itself, and doesn’t support customer self-service upload except on WooCommerce. If you’re holding thousands of certificates with renewal dates, storing and applying details is the wrong shape of product. Verify: ask each vendor to demonstrate verification and renewal tracking against your own certificate types, since that’s the work you’re actually buying, and get the add-on price in writing.

Why there is no single best SST provider, and what these criteria cannot tell you

Cost cannot be compared like for like. Three of the six publish no pricing and a fourth publishes only part of it, so shortlist at least three vendors and treat any complete six-way cost comparison as an estimate.
Certification is not a quality assessment. It’s a Governing Board designation that a system calculates correctly and that states will provide liability relief on that basis. It says nothing about whether a vendor answers the phone or files on time.
No neutral public data on provider service quality exists, so this page doesn’t assess it. Ask each shortlisted vendor for three references at your size and state count.
The CSP-compensated seller test is yours, not the vendor’s. It runs per state against your own Property, Payroll, and places of business, and it changes when your operations do.

You record your provider selection through the Streamlined registration system and can change it later, so this isn’t a one-way door. Read whether to enroll in Streamlined before you run the process at all. This site is published by TaxCloud, one of the six certified providers, which is why every claim above links to a provider’s own materials or to the Governing Board listing.

Frequently asked questions about choosing an SST provider

Does your choice of provider change whether you qualify for free CSP services?

No. Qualification runs on your own Property, Payroll, and places of business, state by state, and the certified scope the states fund is set by the Governing Board rather than by any vendor. Across the five currently offering free services, the terms of that scope are the same. The one choice on your shortlist that changes the answer is picking the provider that isn’t offering them, because the Governing Board lists Exactor as certified and not currently offering free services under the program. Run the CSP-compensated seller test before you run any vendor comparison. It sizes the prize, and no vendor moves it.

In what order should you work the six criteria?

Footprint first, vendor second. Start with the CSP-compensated seller test across your member states, because it’s the largest cost variable on the list and the one thing a vendor can’t change. Then integration fit, which is usually where the decision actually gets made and which eliminates candidates fastest. Then the pricing model, including the non-member states, where most of a multi-state seller’s bill lands. Support terms, audit handling, and certificate handling come last, not because they matter least but because published material won’t settle them.

How many providers should you shortlist, and what do you ask each one for?

At least three. Three of the six publish no pricing at all and a fourth publishes only part of it, so no six-way cost comparison is real and a quote is the only route to a number you can act on. From each vendor, ask for the pricing unit rather than a headline figure, a quote at your current volume and at double it, a separate price for the states outside the program, the connector list with the tier each connector sits on, a response-time target in writing, and three references at your size and state count.

What can you settle from published material, and what has to wait for a call?

Three of the six criteria settle on paper. Your free-service qualification runs on records you already hold. Integration fit you can check against published connector lists, since five of the six publish one, Exactor publishes none, and a missing platform is the fastest elimination on the list. Company scope and the certification date are on the Governing Board listing. The other three don’t settle that way: three of the six publish no price at all, published support commitments run from a 24 hour response target down to nothing, and certificate scope runs from managed capture and processing at one end to storing details without verification or renewal tracking at the other, which tells you nothing about how either behaves against your own certificate types. Take those three to the call.

Sources and last checked

Last checked August 19, 2026. Built only from the providers’ own materials and the Governing Board’s listings, with extracts cached with their URLs and retrieval dates, alongside the per-provider record in the six certified provider profiles. Pages change, so confirm current terms with each vendor. Nothing here is legal or tax advice.