MCP servers for US tax and accounting software: what exists in October 2026

An MCP server is the standard way to let an AI agent use a piece of software: a published list of things the agent can read and do, with the vendor's permissions in front of it. Claude, ChatGPT and Microsoft Copilot all speak it. This page tracks which US tax and accounting tools have one, which have a public API an agent can be pointed at instead, and which have neither. It is the US companion to our Canadian scoreboard.

The short version, as of October 2026: none of the US professional tax packages has an MCP server, shipped or announced. Two practice management platforms have shipped one, three have announced one, and the only tax package with documented public APIs is CCH Axcess.

Tax software

UltraTax CS (Thomson Reuters). None, and no API. Thomson Reuters' API catalogue lists GoSystem Tax, GoFileRoom and ONESOURCE but not UltraTax CS, and a July 2026 request on the TR developer forum for a way to push form data into UltraTax CS is still marked unanswered. The documented path in is SurePrep, where UltraTax CS consumes a SurePrep-side key. GoSystem Tax RS does have an API, with credentials issued during TR onboarding. Thomson Reuters' only MCP announcement to date is for CoCounsel Legal, in May 2026. Sources: TR API catalogue, TR developer forum, GoSystem Tax API, TR and Anthropic, May 2026. Status verified October 2026.

Lacerte (Intuit). No MCP. Intuit publishes a Lacerte SDK, an ODBC driver plus a COM and .NET library, that runs on the machine where Lacerte is installed, needs a developer licence requested by form, and must be granted permission per user. It is a local SDK, not a web API, and its instructions were last revised in June 2026. Intuit's MCP work, announced with Anthropic in February 2026, covers TurboTax, Credit Karma, QuickBooks and Mailchimp. Sources: Lacerte SDK, SDK instructions, Intuit and Anthropic, February 2026. Status verified October 2026.

ProConnect Tax (Intuit). No MCP announced. Karbon, SmartVault and Ignition sync clients, return status, e-signature status and IRS acceptance from ProConnect through an Intuit authorization screen, which means a partner API exists; we could not find public documentation, scopes or self-serve registration for it, and the ProConnect idea-exchange thread asking for an API carries an "Implemented" label with no link. Treat it as partner integrations exist, public access unverified. Sources: Karbon help centre, partner announcement, July 2025, ProConnect integrations. Status verified October 2026.

ProSeries (Intuit). None. No API, SDK or developer program; a community thread opened on August 28, 2026 asking for any supported way to read or write return data was redirected to support on September 2 without a technical answer. Sources: ProSeries community, September 2026, ProSeries integrations. Status verified October 2026.

Drake Tax. None, and no API. Drake's 2025 and 2026 announcements, Drake Tax Online in September 2025 and the SmartExtract beta in July 2026, describe first-party features only, and the partner products page lists audit protection, bank products and GruntWorx. Practice management tools reach Drake by print-to-PDF or file sync. Sources: Drake Tax Online, SmartExtract beta, Drake partner products. Status verified October 2026.

CCH Axcess Tax (Wolters Kluwer). No MCP, but the only US tax package with documented public APIs. The Open Integration kits cover firm, client and staff records, the tax return lifecycle, printing, e-filing and roll-forward, documents, practice and workflow, behind a developer portal and an integrator key. On September 14, 2026 Wolters Kluwer introduced a Designated Vendor Integrator Key so firms can connect third-party tools outside the Marketplace, framed explicitly around agentic workflows. No MCP was mentioned at AICPA ENGAGE in June 2026 or since. Sources: CCH Axcess Open Integration, Designated Vendor Integrator Key, ENGAGE announcement. Status verified October 2026.

Practice management platforms

TaxDome. Announced, not documented. The June 30, 2026 Summer Update promised an Atlas agent, an MCP server for Claude, ChatGPT and Copilot, and a public API, all in beta over the summer and available to every firm by the end of Q3 2026. On October 12, 2026 TaxDome's AI page still lists MCP connectors, the public API and Atlas as coming this fall with a waitlist, and neither the help centre nor the product updates page documents either. Sources: Summer Update recap, TaxDome AI, product updates. Our Canadian page: TaxDome MCP server. Status verified October 2026.

Canopy. Public API shipped, MCP announced. Canopy launched an external API platform on September 30, 2026 with a developer portal, self-serve keys under API Management, and endpoints for clients, contacts, custom fields, files, invoicing, tasks and notes; Plus plans get client and contact data, Premium gets the full set. The same release says Canopy is building an MCP server, with no date. Sources: Canopy press release, CPA Practice Advisor, Canopy API considerations. Status verified October 2026.

Karbon. Documented REST API, MCP announced but not shipped. The v3 API covers contacts, organizations, work items, invoices, files, custom fields, time and webhooks, with release notes as recent as September 23, 2026. A public MCP server was announced with Kai on June 3, 2026; it is still listed as planned on Karbon's roadmap and appears in no developer or help-centre page. Community servers on Pipedream and Zapier exist and are not supported by Karbon. Sources: Karbon developers, API release notes, Kai announcement, roadmap. Our Canadian page: Karbon MCP server. Status verified October 2026.

Financial Cents. Shipped. A remote, first-party MCP server at app.financial-cents.com/mcp, with OAuth 2.1 sign-in, on the Scale plan. It works with Claude, ChatGPT, Cursor and other MCP clients, can view and update clients, projects, tasks and time, read invoices, payments, proposals and files, upload files and send client chat; deletes are deliberately not available. We found no public REST API documentation; other automation runs through Zapier. Sources: Financial Cents MCP, apps and integrations. Status verified October 2026.

Firm360. Shipped in a limited beta, read-only. Firm360 launched a Claude Connector on June 2, 2026 for existing customers on the Premium plan, by waitlist; it answers questions about work in progress, realization, overdue receivables and client profitability and cannot change anything in Firm360. There is no public API; the Zapier app handles client, project and contact automation. Sources: Firm360 Claude Connector, Firm360 summer 2026 update. Status verified October 2026.

Gather and deliver tools

SafeSend and SurePrep (Thomson Reuters). APIs for customers, no MCP. SafeSend exposes APIs authenticated with a Thomson Reuters machine token and a developer section for firm administrators; SurePrep publishes an API with firm-generated keys that creates TaxCaddy clients and document request lists, fires webhooks on upload, and syncs with GoSystem Tax RS. Both are documented in the Thomson Reuters help centre for firms integrating their own tools. Sources: SafeSend developer section, SurePrep API use cases. Status verified October 2026.

Where Armada 1040 fits

The pattern is the same one we found in Canada. Client documents and practice management are reachable by agents today, through shipped MCP servers or documented APIs. The tax packages are not, with CCH Axcess the partial exception. And nothing in between holds a validated record of the inputs a return is built from: which forms a client should have, which have arrived, what each one says, whether the figures reconcile, and what is still missing.

Armada 1040 is coming soon to hold that record. It is the system of record for 1040 inputs, with an MCP server any agent can call. Every input is validated against the complete 1040 input schema before calculation. It does not calculate or file; the completed, document-backed file is handed off to the tax software your firm already runs. Join the waiting list.

How we keep this current

Every entry above links to the vendor pages we read and carries the month it was verified. We re-check this page quarterly, sooner when a vendor has given a date, and we change a status only when something is generally available or publicly documented, never on an announcement. If you work at one of these vendors and something here is out of date, tell us.

This page describes third-party products as documented by their vendors in October 2026. All product names are trademarks of their respective owners, and no partnership or endorsement is implied. Claude is a trademark of Anthropic, PBC. ChatGPT is a trademark of OpenAI. Product availability changes; verify with the vendor before relying on it.