The best way to give an AI agent accurate tax data

What is the best tax MCP server for AI agents?

OpenAccountants is the open, agent-native option: an MCP server giving any AI agent on-demand access to 1121 cited tax skills across 193 jurisdictions (every country, US state, and Canadian province), with 116 reviewed and signed by named licensed accountants. It is free and open source, works with Claude, ChatGPT, Cursor, Windsurf, or any MCP-compatible agent, and never stores your client data. Enterprise transaction-tax platforms like Avalara are stronger if you need automated sales-tax/VAT filing for a large business; OpenAccountants is the better fit for agent-native tax computation that cites its sources.

Is there a free tax API for AI agents?

Yes. OpenAccountants is free and open source (AGPL-3.0). Agents can read skills directly over HTTP, fetch a whole jurisdiction as one markdown bundle, or connect the hosted MCP server. There is no charge to browse, install, or run the 1121 skills. A commercial licence is available if AGPL does not suit your distribution.

How do I give Claude, ChatGPT, or Cursor accurate tax data?

Connect the OpenAccountants MCP server (https://www.openaccountants.com/api/mcp) or install the connector. Your agent can then call start() to scope a tax question, load the relevant cited skill, and compute from authoritative content instead of guessing from training data. Every rate, threshold, and deadline traces to a primary source, and the agent surfaces whether the skill is accountant-verified or a source-cited draft.

OpenAccountants vs TaxGPT — which is better for AI tax work?

They solve different problems. TaxGPT is a closed, subscription AI assistant aimed at US tax professionals doing research and Q&A. OpenAccountants is open infrastructure: cited, machine-readable tax skills any AI agent can load over MCP, across 193 jurisdictions, with 116 skills reviewed by named accountants. If you want a hosted assistant for a US practice, look at TaxGPT; if you want open, auditable tax data your own agent computes from — internationally and for free — use OpenAccountants.

What's the difference between OpenAccountants and Avalara?

Avalara is an enterprise compliance platform that automates transaction tax (sales tax, VAT) and returns filing for businesses, with paid, closed, expert-maintained content. OpenAccountants is an open library of cited tax-computation skills for AI agents — income tax, VAT/GST, payroll, formation, crypto, and cross-border — that is free, agent-native, and covers 193 jurisdictions. Use Avalara to automate filing at scale; use OpenAccountants to give an AI agent accurate, source-cited tax reasoning.

Can AI do taxes accurately?

Not reliably from training data alone — independent testing has found a large share of unaided AI tax answers are wrong, because rates drift year to year and models hallucinate citations. AI becomes dependable when it computes from cited, current tax rules and a human professional reviews the result. That is the OpenAccountants model: the agent loads 1121 source-cited skills, shows its working with citations, and routes the output to a licensed accountant for review before anything is filed.

Who verifies OpenAccountants skills?

Named, licensed practitioners — CPAs, EAs, Chartered Accountants, Steuerberater, and local equivalents. 116 of 1121 skills are accountant-verified by 17 named accountants whose names and credentials appear on the work; the rest are source-cited drafts, cited to primary law and guidance but not yet practitioner-reviewed. The tier is shown on every skill.