DoubleTaxationDoubleTaxation AI agent for Claude, ChatGPT and other assistants
DoubleTaxation can be connected to an AI assistant as an MCP server (Model Context Protocol). The assistant then asks you the questions that matter, and the conclusion is computed by the same rules engine as this website.
What the agent does
- Determines tax residence between two countries: asks the questions one at a time and returns the conclusion, its reliability, the treaty rule, the taxes, the legal basis, court practice and a link to the same result on the website.
- Explains the treaty rules for each type of income.
- Says what to do next: certificate of residence, obligations as a resident and a non-resident, steps when leaving a country, the year of the move.
- Checks whether a country charges an exit tax.
- Counts days of stay from your trips: each country's threshold, Schengen 90/180. Trips are not stored.
- Shows the tax burden on salaries in different countries.
- Finds special tax regimes for people who relocate, are self-employed, invest or receive a pension.
- Compares business forms: sole proprietor or your own company.
24 versions of the service (by home country) and 28 countries are available.
How it works
The assistant picks the version for your home country and calls the server's tools. The server asks the questions one at a time — only those needed in your situation. The assistant asks them to you and passes on your answers. When the answers are complete, the server returns the conclusion.
The conclusion is computed by the rules engine, not by the AI model: the assistant only presents it in your language. The rules are based on the official texts of laws and treaties — see the methodology.
The server stores nothing: answers, trips and amounts are processed in memory only while the request is handled. What you write to the assistant is processed by its provider under its own terms.
How to connect
Claude (web, desktop, mobile)
- Find DoubleTaxation in the Claude connectors directory and connect it.
- Or manually: “Settings → Connectors → Add custom connector”; name — DoubleTaxation, URL —
https://doubletaxation.app/api/mcp, no sign-in.
Claude Code
claude mcp add --transport http doubletaxation https://doubletaxation.app/api/mcpChatGPT
The DoubleTaxation app for ChatGPT has been submitted to OpenAI for review. Once approved, it will appear in the ChatGPT app directory — we will update this page.
Other assistants
Any client that supports remote MCP servers (Streamable HTTP) connects with the same URL, https://doubletaxation.app/api/mcp — no keys, no sign-in.
How to use it
Just describe your situation to the assistant in your own language. For example:
- “I'm a Ukrainian citizen living in Warsaw since March; my family is in Kyiv. Where am I tax resident in 2026?”
- “I work in Germany 8 months a year and receive dividends from the U.S. How is each income taxed?”
- “Compare the tax on a 60,000 EUR salary in Spain, Italy and Poland.”
- “Which tax regimes for people relocating are open in Italy now?”
Answer the assistant's questions as precisely as you can: the conclusion depends on them. At the end the assistant gives you a link that opens the same result on the website, where you can save it as a PDF.
Limits
For individuals only. The result is general information, not legal or tax advice.
Technical documentation for developers: tools, protocol and examples.