Sellers registered through Streamlined Sales Tax can have Avalara or Sovos file in member states at no charge, which Kintsugi cannot offer. Enterprises on SAP, Oracle or Workday usually look at Vertex. Companies whose main exposure is VAT and GST outside the United States compare Fonoa.
- Kintsugi's free plan monitors nexus and classifies products, but registrations and filings start with Starter at $75 per filing or registration.
- International VAT and GST, real-time calculation in NetSuite, QuickBooks or Dynamics 365, API and SSO are Premium features with custom pricing.
- Avalara and Sovos are on the Streamlined Sales Tax list of certified service providers offering free services; Kintsugi and Vertex are not.
- Since South Dakota v. Wayfair (June 21, 2018), states may require remote sellers to collect sales tax without a physical presence.
- Kintsugi runs Vertex's tax engine for its NetSuite customers, so switching to Vertex there can mean keeping the same calculation logic.
Kintsugi automates US sales tax for ecommerce, SaaS and direct-to-consumer companies. It watches where sales cross state thresholds, registers the company, calculates tax, files returns and keeps exemption certificates, and it uses AI to classify products, validate addresses and answer questions through its assistant Kin. The vendor says more than 7,000 businesses use it and that it covers more than 13,000 local taxing authorities.
Kintsugi is young compared with the incumbents, and its pricing is built for companies that start small. That is why buyers compare it: some want to know whether per-filing fees grow faster than a flat contract, some need ERP connectors or international VAT, and some qualify for state-funded free filing that only certain providers can deliver. This page sorts Avalara, Sovos, Vertex and Fonoa by those situations, using vendor and public-sector sources checked on September 26, 2026.
Shortlist: which Kintsugi alternative fits which situation
AvalaraFits sellers who qualify for Streamlined Sales Tax and want the broadest set of connectors and services. Avalara is a certified service provider offering free services in member states; its own packages start at $699 and registration costs $403 per location.
SovosFits companies that combine US sales tax with e-invoicing and indirect tax in many countries. Sovos names coverage of about 200 countries and is also on the Streamlined Sales Tax list of free service providers. Prices are on request.
VertexFits large enterprises running SAP, Oracle, NetSuite, Microsoft or Workday that need one engine across 195 countries and more than 20,000 jurisdictions. Vertex quotes prices only through sales.
FonoaFits digital businesses whose main burden is VAT and GST abroad: tax ID validation in 120+ countries, calculation in 100+ jurisdictions and e-invoicing compliance. Its homepage does not mention US sales tax, and pricing follows a demo.
Three plans, and the line between them decides the bill
Kintsugi's pricing page has three plans. Free costs nothing and needs no credit card. It monitors nexus across the United States and more than 100 countries, audits exposure, classifies products with AI, validates addresses, runs the Kin assistant and connects to Shopify, Stripe, Chargebee and BigCommerce. It does not register or file anything.
Starter adds automated registrations, filings, refunds and amendments, basic exemption certificate management, a virtual mailbox for tax notices and 24/7 chat support. It is priced from $75 per filing or registration and covers US sales tax only. A company registered in 8 states that files monthly in each would trigger 96 filings a year. At the starting price that is $7,200 before any registration fee, so the filing frequency matters as much as the number of states.
Premium has custom pricing with volume discounts. It adds compliance in Canada, the EU, the UK and more than 100 countries, real-time calculation in QuickBooks, NetSuite and Microsoft Dynamics 365, back-filing with voluntary disclosure options, API, SDK and single sign-on, plus a dedicated account team and the Kintsugi Guarantee. There are no transaction fees or long-term contracts in any plan.
Security is not the weak spot. Kintsugi's homepage states SOC 2 Type II and ISO 27001 certification with monitoring through Drata, and it lists an address in San Francisco. Buyers who leave usually do so because of how the plans are cut, not because of trust questions.
One wording deserves a second look. Kintsugi's homepage says every integration is included at no extra cost, while the pricing page lists the NetSuite and Dynamics 365 connectors as Premium-only. Both statements can be true if the homepage means that Premium carries no connector surcharge. Ask for the plan in writing before you rely on an ERP connector.
Checked at the source
What each Kintsugi plan includes
- Nexus monitoring in the US and 100+ countries
- AI product classification and address validation
- Kin assistant, CSV import, no-code connectors
- No registrations and no filings
A monitoring tool, not a compliance service.
Source: Kintsugi pricing page, as of September 26, 2026
Why sales tax needs software at all since 2018
Until 2018 a US state could only require a seller to collect its sales tax if the seller had a physical presence there. In South Dakota v. Wayfair, decided on June 21, 2018, the Supreme Court dropped that rule. The South Dakota law at issue applied to sellers that deliver more than $100,000 of goods or services into the state a year or complete 200 or more separate transactions there.
Other states followed with their own thresholds. For an online shop or a SaaS company, that means tracking sales per state, registering once a threshold is crossed and then filing on the state's calendar. Kintsugi puts the number of local taxing authorities at more than 13,000. Every provider on this page sells some version of the same promise: know where you owe, collect the right rate and file on time.
The Streamlined Sales Tax program adds a twist. Its governing board certifies service providers, and for qualifying volunteer sellers the participating states fund those services, so registration, calculation, filing, exemption certificates and audit support cost the seller nothing in those states. The quiz below tests four facts from this page.
Test yourself
Four facts about switching sales tax tools
Question 1 of 4
In which year did the Supreme Court decide South Dakota v. Wayfair?
Source: Supreme Court of the United States, Streamlined Sales Tax Governing Board, Kintsugi pricing page, as of September 26, 2026
The alternatives, sorted by the reason for switching
Free filing in member states is the strongest argument for Avalara. The Streamlined Sales Tax board lists Avalara among the certified providers that currently offer free services, and its page on Avalara says participating states fund those services for qualifying volunteer sellers. Outside that program, Avalara's pricing page states that its tax calculation and returns package starts at $699, that registration costs $403 per location and that the final price depends on products, connected applications, transaction volume and states.
Sovos is the second certified provider with free services on the list. Its homepage speaks of about 200 countries, 16 billion transactions processed in the last fiscal year and more than 100,000 companies, and it covers e-invoicing, indirect tax and information reporting such as 1099 forms. Sovos presents Sovi AI as part of its platform. Prices come after a call.
Vertex serves the top of the market. Its homepage cites 195 countries, more than 20,000 jurisdictions and customers that include 60 percent of the Fortune 500, with partnerships for SAP, Oracle, NetSuite, Microsoft, Shopify and Workday. Kintsugi itself runs Vertex's engine for NetSuite customers. Vertex is not on the Streamlined Sales Tax list of free service providers, and it quotes only through sales.
Fonoa is a different kind of alternative. It focuses on indirect tax outside the United States: tax ID validation in more than 120 countries, VAT, GST and sales tax calculation in more than 100 jurisdictions, e-invoicing and multi-country returns. Its homepage does not mention US sales tax specifically. A company with modest US sales and a large European or Asian business may pair Fonoa with a US specialist instead of replacing Kintsugi one for one.
Checked at the source
Kintsugi and four alternatives
What each vendor publishes on its own pages and on the Streamlined Sales Tax list.
| Avalara | Package from $699; registration $403 per location | Listed | Not stated on pricing page |
| Fonoa | On request | Not listed | 100+ jurisdictions for calculation |
| Kintsugi | Free plan; Starter from $75 per filing | Not listed | US plus 100+ countries in Premium |
| Sovos | On request | Listed | About 200 countries |
| Vertex | On request | Not listed | 195 countries, 20,000+ jurisdictions |
Source: vendor homepages and pricing pages, Streamlined Sales Tax CSP list, as of September 26, 2026
Self-check
Which Kintsugi alternative fits us?
Up to four yes or no questions based on vendor and SST pages as of September 26, 2026. Orientation, not tax advice.
Is most of your indirect tax exposure outside the United States?
What our directory shows about tax tools
Our directory lists 43 tools with tax as their main category. The group is mixed: sales tax and VAT engines such as Kintsugi, Avalara, Sovos, Vertex and Fonoa sit next to AI research assistants for tax advisors. 16 of them name the United States as a strong market and 7 name Germany.
Prices are hard to find in this category. 29 tools publish no price, and the tools with a free plan can be counted on one hand: 5. That free plan is a real difference for a small seller who first needs to know whether it has nexus anywhere. The full list of tax automation tools shows every profile with sources, and the wider tax and audit category adds audit and internal control tools.
Source: ai-toolfinder directory, live count.
Sources: [10]
Moving sales tax compliance without missing a filing
Kintsugi has no long-term contracts, so the contract is rarely the obstacle. The filing calendar is. Every state registration comes with its own due dates, and a return that falls between two systems is the typical failure in a switch. Pick a cutover after a filing period closes in all your states, and let the new provider file the first period while Kintsugi's data stays available for reference.
Move four sets of data. First the registrations: state, account number and filing frequency for each. Second the exemption certificates for B2B customers, since an auditor asks for them years later. Third the product tax codes: export Kintsugi's classification per product and check it against the new system's own codes. Fourth the tax notices that arrived in Kintsugi's virtual mailbox, so no deadline from a state letter gets lost.
If you move to a Streamlined Sales Tax provider, check which of your states are members and register through the program where it applies. Our review method explains how we verify vendor statements before we list them. The checklist below stays saved in this browser.
Checklist
Switching away from Kintsugi
Your ticks stay saved in this browser. Copy the list into your project plan.
Your progress stays saved in this browser.
Sources
- Kintsugi, Pricing (as of September 2026)
- Kintsugi, Homepage
- Supreme Court of the United States, South Dakota v. Wayfair, No. 17-494 (June 21, 2018)
- Streamlined Sales Tax, Certified Service Providers list
- Streamlined Sales Tax, Avalara CSP details
- Avalara, Pricing (as of September 2026)
- Sovos, Homepage
- Vertex, Homepage
- Fonoa, Homepage
- ai-toolfinder, Kintsugi alternatives (directory data, as of September 26, 2026)
