Simplify Sales Tax: an independent guide to the Streamlined Sales Tax (SST) program

Simplify Sales Tax is an independent guide to the Streamlined Sales Tax (SST) program, the agreement among 24 states to run sales tax administration the same way and, for sellers who qualify, to pay a certified provider to file their returns. Every page here answers one question about the program, and every factual claim traces to a primary source you can check.

It’s written for founders and finance leads at multi-state US brands who are already collecting somewhere and want to know whether this changes their number. It’s published and funded by TaxCloud, one of the six certified providers it profiles, and it holds all six to the same criteria. Who publishes this site says what that means.

Start with these five Streamlined Sales Tax pages

Table: the five pages most readers of Simplify Sales Tax need first, and the answer each one gives.

Page	The short answer
What is the Streamlined Sales Tax program?	Twenty-four states administer sales tax the same way, one registration opens all of them, and where you qualify the state pays a certified provider to file for you. Not a tax break, and it doesn’t touch what you already owe.
Which businesses should enroll in SST?	It’s a count: your states, the full member states among them, and the ones where you keep no premises, stock, or payroll. A good number of those and you’re a clear yes. Two or three, and the obligation in each is most of what you get.
Who qualifies for free CSP services?	A member state pays your provider only where you meet all five criteria in that state, over the 12 months before you register there. The criteria in the contract’s own words.
How to register for SST, step by step	One free application, the states you pick, and a start date for each. What to have ready, and the two decisions you can’t undo.
SST Certified Service Providers: the complete list	Six are certified, five currently offer free services to qualifying sellers. What each publishes about price, where it stops, and why certification is a designation rather than a recommendation.

Browse the Streamlined Sales Tax guide by topic

Every page on Simplify Sales Tax sits in one of these topics. Pick the one that matches the decision in front of you, or scan the full list below.

Topic	What is there	Pages
The program	What Streamlined Sales Tax is, how the machinery works, who runs it, and what a Certified Service Provider is.	5
Should you enroll	Who comes out ahead, who does not, the free-services test, the risks, amnesty, and the mid-market case.	7
Registering and filing	The registration form step by step, what you owe afterwards, the simplified return, and audits with a CSP.	6
States	The 24 member states, each with its own page on what changes there and what does not.	24
SST alongside the rest	How the program sits next to economic nexus, marketplace facilitator laws, and the states outside it.	3
Providers	All six SST Certified Service Providers profiled on the same criteria, compared, priced, and how to choose or switch.	12
Reference	The glossary, who publishes this site, how it is sourced, and the corrections log.	4

The Streamlined Sales Tax program: what it is, how it works, who runs it

Read these in order the first time. Every other page on Simplify Sales Tax assumes you know what the Streamlined Sales Tax program is and what a Certified Service Provider does.

What is the Streamlined Sales Tax (SST) program?Twenty-four states agreed to run sales tax the same way and to pay a certified provider to handle the filing for sellers who qualify. What that gets you, what it costs, and who it actually helps.
How does the Streamlined Sales Tax program work?24 states run sales tax administration off one common rulebook, take registration for all of them through one system, and pay a certified provider to do the filing for sellers who qualify. The machine end to end, and where it stops.
Who runs the Streamlined Sales Tax program?The Streamlined Sales Tax Governing Board is a compact of the 24 member states, not a federal tax agency. What that means when you need an answer about your own sales tax, and who can actually give you one.
What is a Certified Service Provider (CSP)?A CSP is a company the member states certified to run your sales tax: calculating it, filing the returns, and sending the money. Where you qualify, the state pays the provider instead of you.
CSP vs CAS vs standard sales tax software: what is the difference?Three things get sold as sales tax software and only two carry any standing in the program. Which one you buy decides who files your returns, who pays for the software, and who carries the loss when the tax comes out wrong.

Should you enroll in the Streamlined Sales Tax program?

The decision pages. Whether Streamlined Sales Tax pays off for your footprint, the test that decides whether the states pay your provider, and the shapes of business it doesn’t fit.

Which businesses should enroll in the SST program?Enrolling pays off when enough of the states you already collect in are member states where a state, rather than you, pays your provider. Four counts you can run this afternoon, how to read the answer off them, and the profiles that sit either side of the line.
What are the benefits of the Streamlined Sales Tax (SST) program?One registration, free CSP services if you qualify, uniform definitions and sourcing, free rate data, a uniform electronic return, narrow liability relief, and amnesty in one state. What each is worth, and where each stops.
Who qualifies for free CSP services in the SST program? The CSP-compensated seller testA member state pays your certified provider only where you meet all five criteria in that state, over the 12 months before you register there. The five criteria in the contract's own words, what each one means for a business with stock or staff on the ground, and the records to pull to check.
Is the Streamlined Sales Tax program worth it for a mid-market brand?The program is sized to a footprint, not to a seller, and nothing in it measures your revenue. It pays off where your states are member states and your warehouses, stores, and people are not, and the qualification test decides where that is, one state at a time.
Which businesses should not enroll in the SST program?Enrolling in the Streamlined Sales Tax program is elective, and five business shapes get the least out of it: a small multi-state footprint, international-first revenue, majority-wholesale volume, a deep SAP or Microsoft Dynamics requirement, and a platform missing from the published connector lists. Why each one, and what decides it instead.
What are the risks of enrolling in Streamlined Sales Tax (SST)?Registering commits you to collect and file in every state you select, from a registration date you cannot change, with a return expected each period. What free CSP services are conditional on, where liability relief stops, and what registering never touches.
Streamlined Sales Tax (SST) amnesty: what it covers and what it does notAmnesty covers uncollected sales or use tax, interest, and penalty for the period before you registered, in the one state offering it at this time. All five exclusions, the three conditions, and why the order you do things in decides whether you get it.

Registering and filing under SST

The mechanics, from the registration form to what you owe every period afterwards, including the periods with nothing to report and the audits that arrive later.

How to register for SST, step by stepOne free application, the states you pick, and a start date for each. What to have ready, what happens after you hit submit, and the two decisions you cannot undo.
What are the requirements for enrolling in the SST program?There is no eligibility test to enroll in Streamlined Sales Tax: no fee through the states' shared registration system, no revenue floor, no minimum number of states, and any seller may register. The requirements are the information you bring and the collection and filing obligation you accept in every state you select.
What are your ongoing obligations after registering for SST?The recurring calendar after you register: collect from your registration date, file a return in every state you registered in every period including the empty ones, handle tax on your own purchases yourself, and reconfirm your free-services status in writing. Plus the changes that quietly end it.
How does the SST program simplify sales tax filing?The member states agreed on the parts a seller cannot control: one registration across the states you pick, published rate and boundary data, one shared library of product definitions, and a single return per state per period. What that changes, what it leaves alone, and why free rate data is not something you have to enroll to get.
What is a Simplified Electronic Return (SER) in the SST program?The SER is the Streamlined program's uniform return: one filing per state per period covering every jurisdiction in that state, accepted by all 23 full member states. Tennessee allows it only for remote sellers with no location in the state. Who files it, what goes on it, and what it takes to file one yourself.
How do sales tax audits work in an SST member state when you use a CSP?In a member state where you qualify as a CSP-compensated seller, the state takes its audit questions to your Certified Service Provider instead of to you. Where you do not qualify, it contacts you directly. What the provider handles, what the liability relief actually covers, and what stays yours either way.

The 24 Streamlined Sales Tax member states

Twenty-three full members plus Tennessee, the only associate member, out of the 45 states with a general sales tax. Start with the complete list of SST member states, then the state you’re checking.

Arkansas Georgia Indiana Iowa Kansas Kentucky Michigan Minnesota Nebraska Nevada New Jersey North Carolina North Dakota Ohio Rhode Island South Dakota Tennessee Utah Vermont Washington West Virginia Wisconsin Wyoming

SST alongside economic nexus, marketplace laws, and the other states

Three pages on how the Streamlined Sales Tax program sits next to the rules you already live with. None of them changes whether a state can make you collect; they change how you register, file, and who pays for the work.

SST states vs non-SST states: what you still oweThe Streamlined program reaches 24 of the 45 states with a general sales tax. In the other 21 nothing about it applies. What runs differently on each side of the membership line for a seller with nexus in both, and what does not change anywhere.
How SST and economic nexus interactEconomic nexus decides whether a state can make you collect. The Streamlined program decides how you register, file, and who pays for the work. Crossing a threshold does not by itself cost you free CSP services, and the condition attached to that comes from the providers' contract rather than from the Governing Board.
SST vs marketplace facilitator lawsThey are not alternatives. A marketplace facilitator law is one state's rule about who collects on a marketplace sale. The Streamlined program is 24 states agreeing on administration. What a mixed-channel seller actually has to do, and what still lands on you after the marketplace has remitted.

The six SST Certified Service Providers

Six companies are certified by the Governing Board to do the work the states pay for. Simplify Sales Tax profiles each on the same criteria and reaches no verdict on which to choose; that decision is yours, and program choice and provider choice are separate here.

SST Certified Service Providers: the complete listSix providers are certified by the Streamlined Sales Tax Governing Board. Five currently offer free CSP services to qualifying sellers, one does not. What each one is, what it publishes about price, where it stops, and why certification is a designation rather than a recommendation.
SST CSP comparison: all six providers side by sideAll six providers certified by the Streamlined Sales Tax Governing Board on the same dimensions: free CSP services, published pricing, pricing model, integrations, support, company scope, and best fit, plus at least one real limitation each. One publishes complete pricing, one publishes part of it, and three publish none. Checked 2026-08-19.
What does an SST Certified Service Provider cost?The states pay your provider for the certified work in the full member states where you qualify. You pay for everything else. Of the six certified providers, one publishes complete tier pricing and three publish none.
How to choose an SST Certified Service ProviderSix criteria for comparing the six certified providers, and four buyer scenarios worked on each provider's own published record. Three of the six publish no pricing at all, and this page names no best provider.
How to switch SST providers without losing coverageYour Streamlined registrations, your SSTID, and your per-state registration dates stay with you when you change Certified Service Providers. The Governing Board publishes no procedure for the change, and the filing gap between the old provider's last return and the new one's first is yours to cover.
Which CSP specializes in SST? How the six certified providers are builtNone of the six certified providers sells SST on its own, and the certified services are identical at all of them. What differs is scope: for two, United States sales tax is the whole business, and for the others SST sits inside a portfolio spanning global VAT, e-invoicing, excise verticals, or an accounting suite. Scope checked August 19, 2026.

The six profiles, in the same order as the provider module at the foot of every page:

Avalara TaxCloud Sovos AccurateTax Avior Exactor

Reference pages for Simplify Sales Tax

The glossary of Streamlined Sales Tax terms, who publishes this site, how it’s sourced, and the log of what we’ve corrected.

Streamlined Sales Tax glossaryDefinitions of the terms the SST program runs on, checked against primary sources: SSUTA, CSP, CAS, CSP-compensated seller, the four seller models, and where those terms get misused.
About Simplify Sales TaxAn independent guide to the Streamlined Sales Tax program. It is published and funded by TaxCloud, one of the six certified providers the site covers.
Editorial standardsHow this site sources facts, covers all six providers, logs corrections, and handles being funded by a provider it covers.
CorrectionsEvery substantive correction to this site, with the date and what changed, plus the open questions we could not resolve and what each one costs the site's copy.

What Simplify Sales Tax doesn’t cover

One program, the Streamlined Sales Tax program, in the 24 states that participate in it. It isn’t a guide to US sales tax generally and it isn’t tax or legal advice, so confirm anything here with a tax professional before you act on it. It doesn’t publish tax rates, nexus thresholds, or taxability rulings, because those vary by state and change often. And there’s nothing here to buy: no advertising, no sponsored content, and no provider can pay for placement, including the one that funds the site. If something here is wrong, write to corrections@simplifysalestax.com.