# Introduction ### **Understanding the Belgian Mandate** Belgium is transitioning to a mandatory structured e-invoicing model for all business-to-business (B2B) transactions. This mandate is a significant shift from traditional invoicing (paper or PDF) and requires a new approach to compliance. * **Mandatory Deadline:** From January 1, 2026, all VAT-registered businesses in Belgium must be able to issue and receive structured electronic invoices for their B2B transactions. * **What is a "Structured E-Invoice"?** A structured e-invoice is not a PDF file. It is a machine-readable data file, specifically an XML file, that must conform to the European Standard EN 16931 and the Peppol BIS 3.0 format. From the 2026 deadline, unstructured formats like paper invoices or PDFs sent via email will no longer be considered legally compliant for B2B transactions. --- # 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://docs.cleartax.in/product-help-and-support/for-large-businesses/cleartax-e-invoicing-belgium/introduction.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.