# API Description - [VAT Rates](https://documentation.vatzen.com/api/vat-rates.md): Obtain official EU VAT rates, full and reduced, for different categories. - [VAT Number Validations](https://documentation.vatzen.com/api/validate-vat-number.md): Highly-secured, real-time EU VAT number validation that allows you to check the VAT number for a business. It's helpful when you sell to business customer and do not need to add VAT. - [VAT Prices Calculations](https://documentation.vatzen.com/api/calculate-price.md): Using our price endpoints, you may request the API to calculate VAT compliant prices for you. - [Generate Invoce](https://documentation.vatzen.com/api/generate-invoce.md): We created an invoicing service strictly in accordance with the requirements for VAT compliant invoicing published by the EU tax authorities. You can easily issue invoices VIA our API or dashboard. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://documentation.vatzen.com/api.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.