At the start of 2026, structured electronic invoicing is no longer an upcoming regulatory change in Belgium. It is now the standard operating framework for domestic B2B transactions between VAT-registered companies. The legal mandate is in place. The ecosystem is active. The real question has shifted from “when will this happen?” to “how well is the market actually coping with it?”

On 2 December 2025, Belgium’s Federal Public Service Finance confirmed two essential points: 1. The Belgian B2B e-invoicing mandate enters into force on 1 January 2026. Structured electronic invoicing becomes mandatory for all domestic B2B transactions between VAT-liable companies. 2. A three-month tolerance period will apply during Q1 2026. But this is not a postponement, the obligation remains fully active.The tolerance applies only to businesses that have begun the