Use NL Tax Calculator in ChatGPT and Claude

The connector address

It is an MCP server (Model Context Protocol), the open standard ChatGPT, Claude and other assistants use for tools. No account, no key, and nothing you ask is stored.

Add it to Claude

1. Open Claude, go to Settings → Connectors and choose Add custom connector.
2. Name it “NL Tax Calculator” and paste the address above.
3. In a chat, turn the connector on and ask, for example: “What is my net salary on €72,000 with the 30% ruling?”

Add it to ChatGPT

1. In ChatGPT, open Settings → Apps & Connectors. Custom connectors need developer mode, under Advanced settings (available on paid plans).
2. Choose Create, name it “NL Tax Calculator”, paste the address above and choose no authentication.
3. Start a chat, add the connector from the tools menu and ask your question.

Menu names change now and then; look for “connectors” or “MCP” in your assistant’s settings.

What it can calculate

• Dutch net salary (take-home pay): Gross-to-net salary in the Netherlands for 2026: income tax with the general and labour tax credits, optional 8% holiday allowance on top, the 30% ruling (with its salary norm and cap) and a pension contribution. Returns net per month and per year and the effective tax rate. Single employee below state pension age.
• Dutch Box 3 wealth tax: Box 3 tax on savings and investments in the Netherlands for 2026 (the notional-return system): the tax-free allowance, the notional return on savings, investments and debts, and the 36% tax. Optionally for fiscal partners (double allowance).
• Highly skilled migrant / EU Blue Card salary check: Checks whether a salary meets the 2026 IND salary requirement for a Dutch highly skilled migrant (kennismigrant) permit or an EU Blue Card. Holiday allowance does not count; a 13th month counts only when paid monthly. Also checks the 30% ruling salary norm.
• Losing a job in the Netherlands: severance, WW, visa and 30% ruling: For an employee whose Dutch contract ends: the statutory transition payment (transitievergoeding), unemployment benefit (WW) amount and duration under UWV rules, and for expats the highly skilled migrant / Blue Card search period end date and the last start date for a new job to keep the 30% ruling.
• What the 2027 Dutch tax plan means for a salary: Compares income tax on a gross salary in 2026 with the Belastingplan 2027 proposal (presented on Prinsjesdag 2026, a proposal until Parliament votes): brackets and tax credits, and the 30% ruling dropping to 27% unless it started before 2024.
• Dutch transfer tax on buying a home: Overdrachtsbelasting in 2026 when buying a home in the Netherlands: 2% for a home you live in, 0% for first-time buyers aged 18-34 up to a €555,000 price, 8% for other homes.
• US tax for Americans living in the Netherlands (FEIE vs Foreign Tax Credit): For a US citizen or green-card holder with a Dutch salary: Dutch tax, the creditable part (AOW/Anw premiums are not creditable under the US-Dutch totalization agreement), and the US tax for 2026 under the Foreign Earned Income Exclusion and under the Foreign Tax Credit, incl. the child tax credit and its refundable part.

Good to know

• Answers are estimates with the official Dutch rates, not tax advice, and each one links to the calculator with every step shown.
• Only the numbers in your question are sent to the calculator; not your name, not the chat.
• The 2027 figures follow the government’s proposal until Parliament has voted.