Kintsugi Review
Kintsugi is AI-native sales tax software that monitors nexus for free, then registers, files and remits US sales tax for small and mid-sized e-commerce and SaaS sellers from $75 per filing, with VAT, ERP calculation and API access on custom-priced Premium.
Independently scored, one dimension at a time. Every dimension is sourced, and we say whether a claim is published, reported, or estimated.
A hosted MCP connector announced 18 September 2026 gives Claude 46 read-only tools over live nexus, filing, registration and transaction data; Kintsugi's help center says users add it from Claude's connector directory and sign in with the app login. A separate docs MCP lists 51 API operations, 22 of them writes, behind a Premium API key that cannot be scoped to read-only. Kin and AI product classification run on every plan including Free; accuracy and time-saved figures are vendor-claimed.
Kintsugi lists 60+ integrations with pages for Shopify, Amazon, Walmart, Stripe, Chargebee, Zuora, NetSuite, Sage Intacct, QuickBooks Online, Xero and Business Central (checked 4 October 2026). ERP connectors calculate tax on invoices as they are created, but real-time engine integrations are Premium-only. Shopify checkout tax stays with Shopify while Kintsugi reads the orders to file, and HR connectors such as Deel feed physical nexus.
Signup is self-serve with no onboarding or implementation fees, and the getting-started docs say the first three setup steps take an afternoon while registrations move at each state's pace. The FAQ claims a nexus audit, registration and back-filing in 3 to 5 days, which is a vendor claim. ERP calculation adds work: Sage Intacct needs a custom XML package that sets up smart events, per Kintsugi's 27 July 2026 walkthrough.
Starter includes 24/7 live chat with same-day human responses, and Premium adds a dedicated account team and SLA-backed support (pricing page, 4 October 2026). The Shopify App Store listing shows 4.8 stars from 35 reviews, and Kintsugi's own pages cite 4.6 out of 5 on G2 from 55 reviews. SLA terms are not public, and the Free plan has no live chat.
Free at $0 and Starter from $75 per filing or registration are published with a feature table and FAQ (checked 4 October 2026). There are no onboarding, implementation or transaction fees, and billing is month-to-month. The score stays in the 70s because Premium, which holds real-time calculation, API access, non-US filing and the guarantee, is custom priced with no public benchmark.
US sales tax runs on every paid plan, and the coverage page marks 101 countries live and 21 coming soon (counted 4 October 2026), but non-US filing needs Premium. NetSuite customers get Vertex's O Series engine with rules for 19,000+ jurisdictions; elsewhere Kintsugi uses its own engine, which it says updates daily from primary sources. Use tax filing arrived on 24 September 2026, and Kintsugi lists no e-invoicing product.
Kintsugi says 7,000+ businesses use it (pricing and integration pages, checked 4 October 2026), up from 4,500+ customers and 159 million transactions worth $12.7 billion in 2025 (vendor post, 30 December 2025). The API docs set the throttle at 10,000 requests a minute, but products are created one per request. Multi-entity, multi-country and volume pricing all sit in Premium, and Portfolio lets a firm run many client organizations from one login.
Kintsugi's security page (checked 4 October 2026) cites SOC 2 Type II and a GDPR data processing addendum, but no SOC 1 report, which matters when a tax engine feeds audited financials. Filings pass an approve step in the app, and the 24 September 2026 use tax post says the team reviews every filing before it goes out. The guarantee pays penalties and interest caused by Kintsugi's errors, yet the pricing page limits it to Premium and the terms updated 29 September 2026 cap liability at 12 months of fees.
Low-cost US filing for small sellers; calculation, global VAT and the guarantee need custom-priced Premium
Written by the Audit Friendly research team. No vendor edits, no sponsored placement.
What you are buying is a filing service with software around it. The Free plan monitors nexus across the US and 100+ countries at no cost. Starter registers, files and remits US sales tax from $75 per filing or registration (published, checked 4 October 2026), with no onboarding fees, no transaction fees and month-to-month billing. AI classifies products, Kin answers questions from account data, and Kintsugi says its team reviews every filing before it goes out. Vertex holds a minority stake and powers the NetSuite engine.
The catch is what the published price leaves out. Real-time calculation on ERP invoices, API access, filing outside the US, VDAs, SSO and the Kintsugi Guarantee all sit in Premium, which is custom priced. Per-filing pricing also climbs with filing frequency: a state filed monthly costs about $900 a year at the entry rate (Audit Friendly estimate), above Avalara's published $799 per state per year. Kintsugi publishes SOC 2 Type II only, its terms cap liability at 12 months of fees, and the company was founded in 2022.
Before signing, get the Premium quote in writing with the ERPs that will calculate in real time and the countries that will be filed. Ask whether the guarantee covers tax as well as penalties and interest, and how its limit interacts with the 12-month fee cap in the terms. Confirm who pays state registration fees, whether a SOC 1 report or bridge letter exists, and how returns, registration credentials and history come back to you within the 60-day export window after cancellation.
- A Shopify, Amazon or Stripe seller that just crossed nexus in a handful of states and wants filing handled without an annual contract.
- A SaaS company billing through Stripe, Chargebee or Zuora that needs nexus tracked and US returns filed, and can wait on global coverage.
- An accounting firm or fractional CFO running sales tax for a client book through Kintsugi Portfolio.
- A public company or audit-heavy business that needs a SOC 1 Type 2 report on its tax engine; Kintsugi publishes SOC 2 Type II only.
- A seller filing monthly in many states that wants the lowest bill: per-filing pricing climbs with frequency, so price Premium against per-state plans.
- An enterprise that needs e-invoicing mandates, SAP or Oracle connectors, or deep tax-engine configuration; Kintsugi lists none of these.
The jobs a tax team actually hires Kintsugi for
Jobs, mapped to how finance teams actually buy.
Find out where you already owe before a state does
Connect Shopify, Stripe, QuickBooks or a CSV, import the prior calendar year, and Kintsugi maps economic and physical nexus with threshold alerts. The Free plan includes historical liability auditing, so a founder sees back-tax exposure before paying for anything.
Hand off monthly filing across dozens of states
Vincero, a Shopify brand, says it went from 15 to 20 state notices a month to none after switching in May 2025, with 16 months of on-time filing. These outcomes are vendor-claimed. Once the first return in each state is approved, Kintsugi files and remits on schedule.
Clean up back taxes and register late
Kintsugi offers back filing, VDAs and overpayment recovery, though VDAs need Premium. The 3 to 5 day figure is vendor-claimed and depends on each state's processing time.
Run sales tax for a client book
Kintsugi Portfolio, generally available since 4 March 2026, puts every client's registrations, filings and nexus in one dashboard with bulk actions. Firms can refer clients for recurring commissions or white-label the platform, and the BDO Alliance USA added Kintsugi to its vendor program on 1 October 2026.
Calculate tax inside NetSuite with Vertex rules
On Premium, Vertex's O Series engine calculates tax on NetSuite transactions as they are created, on Legacy Tax or SuiteTax, while Kintsugi tracks nexus and files. Kintsugi says it can run beside an existing Avalara bundle during evaluation.
Ask Claude about filings and nexus
A controller can ask Claude what is due this month or where nexus is approaching and get answers from live account data. The connector cannot change anything, so filing approval stays in the Kintsugi app.
Watch the same task in each tool
Forget the 40-row feature grid. Pick a finance workflow and see how this tool and its closest peers actually do it, with our verdict on who wins for whom.
Compare on what matters
What it actually costs
Here's what it really costs: published rates where a vendor lists them, aggregated quote data where they don't, plus a path to your own number.
Nexus monitoring in the US and 100+ countries, AI product categorization, Kin, CSV imports and no-code integrations. No filing.
US registrations, filings and remittance, amendments, basic exemption certificates, virtual mailbox, onboarding help and 24/7 live chat.
Adds real-time ERP calculation, API, SDK and SSO, non-US coverage, VDAs, bulk certificates, a dedicated account team and the Kintsugi Guarantee.
No onboarding, implementation or transaction fees on any plan (published).
A few states charge their own registration fee, paid by the customer on top of Kintsugi's fee.
What it actually takes to go live
The pricing page (checked 4 October 2026) marks real-time tax engine integrations, API access, and Canada, EU, UK and other country coverage as Premium-only. Starter registers, files and remits US sales tax from transactions it syncs. A seller that needs tax on QuickBooks, NetSuite or Business Central invoices, or a checkout API, is buying Premium, which is custom priced. Get that number before comparing Starter with per-state plans.
Starter charges from $75 per filing or registration. A state where you file monthly is 12 filings, about $900 a year at the entry price, while a quarterly state is about $300 (Audit Friendly estimate). Avalara publishes $799 per state per year for its Core Compliance plan, so a seller with many monthly states should price both. Kintsugi's own glossary notes that states set filing frequency by tax collected and move growing businesses to monthly filing.
The pricing page lists the Kintsugi Guarantee, which pays penalties and interest caused by Kintsugi's calculation or filing errors, only on Premium, while the FAQ promises to cover penalties for a missed deadline without naming a plan. The terms updated 29 September 2026 cap Kintsugi's liability at fees paid in the prior 12 months and apply that cap to filing claims. Customers must report a filing claim within 180 days of the notice and fund remittances three business days before each due date.
Kintsugi's Shopify page says Shopify collects tax at checkout and Kintsugi reads the orders to calculate what is owed and file, without touching the checkout. If Shopify's rate settings under-collect, the gap shows up later as liability owed. Kintsugi's tax estimate API and SDKs can calculate at a custom storefront, but API access is Premium.
Kintsugi's security page and terms reference an annual SOC 2 Type II audit and a GDPR data processing addendum (checked 4 October 2026). Kintsugi does not publish a SOC 1 Type 2 report, which external auditors usually request when a service provider calculates and remits tax that hits the financial statements. Avalara's trust center lists SOC 1 Type 2 for its most widely used products. Ask Kintsugi for a SOC 1 or a bridge letter before go-live if you are audited.
Kintsugi's MCP docs say API keys are not scoped and there is no read-only variant. The docs MCP server listed 51 tools on 4 October 2026, and 22 of them change data, including approve-filing and deregister-registration. The docs page itself says 17 of 41 tools write, so the live list has grown past the documentation. Use a test organization key for experiments and the read-only OAuth connector for everyday questions.
Scored on what an outside agent can actually reach: the documented API, how it authenticates, and whether the vendor ships an MCP server.
Exists: Yes. Kintsugi announced its MCP server on 18 September 2026, and the endpoint at mcp.trykintsugi.com answered with OAuth metadata scoped to read:user_data when checked on 4 October 2026. A second server at docs.trykintsugi.com/mcp targets developers.
Scope: The account connector is read-only, with 46 tools across dashboard, nexus, transactions, filings, registrations, products, connections, organizations and addresses. It cannot file, register, edit a transaction or move money. The docs server lists 51 tools that call the production API with a key from the connection headers, and 22 of them change data, including approve-filing, create-registration and deregister-registration (live tool list, 4 October 2026).
Turnkey: For Claude Pro, Max, Team and Enterprise users, Kintsugi's help center says to find Kintsugi in Claude's connector directory under Settings, Connectors, and sign in with the app login, no API key. The docs server needs an admin-created API key and organization ID, API access is Premium-only, and keys are not scoped, so a key handed to an agent carries the organization's full access.
In-product AI: Kin, launched 28 April 2026, answers questions grounded in account data and cites its sources, according to Kintsugi. Kintsugi Intelligence suggests product categories and fills in addresses for human approval. Outcome claims such as cutting compliance costs by 40 percent or more are vendor-claimed.
Kintsugi, kept current
Kintsugi now imports purchases, calculates use tax with credit for vendor-charged tax, and files it, with staff review of each filing. Available for US businesses.
A read-only MCP server with 46 tools across nine account areas; Kintsugi says Claude users add it from the connector directory with the Kintsugi login. It cannot file, register or pay.
Kin answers sales tax, VAT and GST questions grounded in account data and cites sources, according to Kintsugi. It is included on every plan, including Free.
A multi-client dashboard for firms to manage registrations, filings and teams across client organizations, with bulk actions. Turned on through support.
Pairs Vertex's O Series tax engine with Kintsugi's product categorization, nexus monitoring, registrations and filing. Kintsugi sells it for NetSuite, and SuiteTax support was announced on 15 December 2025.
TechCrunch reported a $15 million Vertex investment for a 10 percent stake plus $3 million from existing investors, at a $150 million post-money valuation.
Kintsugi FAQ
On Starter, Kintsugi charges from $75 per filing or registration (published, checked 4 October 2026), with no onboarding, implementation or transaction fees. Ten states filed quarterly is 40 returns a year, about $3,000; ten states filed monthly is 120 returns, about $9,000 (Audit Friendly estimates at the entry price). New registrations add $75 each plus any state fee.
If you need tax calculated on ERP invoices, API access, VAT or GST filing, or the Kintsugi Guarantee, you are on Premium, which is a custom flat rate with volume discounts. No public benchmark for Premium was found, so ask for a written quote that names the states, countries and filing frequencies it assumes.
Subscriptions bought through Kintsugi's site bill monthly with no long-term contract unless a customer agreement says otherwise, and cancellation takes effect at the end of the current paid period under the terms updated 29 September 2026. Kintsugi described its Vertex-powered NetSuite offering as one annual plan in December 2025, so confirm the term on any Premium quote. Kintsugi can change fees on 30 days' notice.
Within 60 days after a subscription ends, Kintsugi will export customer data in a commonly used format or give limited access to retrieve it, at no charge, and will provide copies of returns filed and registration credentials held on your behalf. Its filing authority continues only for periods ending before cancellation with due dates in the following 30 days, after which filings and preparer-of-record changes are yours.
Kintsugi's docs say connecting data, importing the prior calendar year and configuring the business take an afternoon, and registrations land over days at each state's pace. The FAQ claims nexus audit, registration and back-filing in 3 to 5 days, which is a vendor claim.
The finance lead does most of it: connect sources, approve AI product categories, record physical presence, set up ACH and approve the first filings. Starter includes onboarding help and Premium adds a dedicated onboarding manager. ERP calculation needs extra setup, such as a custom XML package in Sage Intacct or choosing Legacy Tax or SuiteTax in NetSuite.
Claude can read it. Kintsugi's hosted MCP connector, announced 18 September 2026, works with Claude Pro, Max, Team and Enterprise plans, and Kintsugi's help center says to add it from Claude's connector directory and sign in with the Kintsugi app login. Its 46 tools read the dashboard, nexus, transactions, filings, registrations, products, connections, organizations and addresses, and none of them can file, register, edit or pay.
Writes are possible through a separate docs MCP at docs.trykintsugi.com/mcp, which calls the production API with an API key and includes tools such as approve-filing and create-registration. API access is Premium-only and keys are not scoped, so treat that path as an admin-configured integration with full account rights.
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