Executive summary

Belgium authorities announced on 2 December 2025 that a tolerance period will apply during the first quarter (Q1) of 2026 for the upcoming mandatory business-to-business (B2B) e-invoicing rules. During this period — and only if specific conditions are met — penalties will be waived for certain breaches related to e-invoicing.

Importantly, this does not imply a delay in the go-live date for mandatory B2B e-invoicing, which remains 1 January 2026. Instead, the tolerance period reflects a pragmatic approach for businesses that timely prepared but are still dealing with issues outside their control. Planning ahead remains essential.

Further, on 3 December 2025, a new draft law on the B2B e-invoicing mandate was published.

Tolerance period during Q1 2026

What breaches are covered?

Specific breaches covered by the tolerance period include:

• A business does not yet have the technical means to send and/or receive structured electronic invoices (entirely or for certain transactions, e.g., self-billing).
• A business cannot issue a mandatory structured electronic invoice because its own system — or that of a third-party provider — is not yet capable of issuing a valid e-invoice.

What does this mean for businesses?

Tax exposure will be temporarily reduced while businesses finalize their Belgian e-invoicing setup and collaborate with e-invoicing vendors.

Businesses might need to manage multiple accounts receivable/accounts payable (AR/AP) processes from 2026, depending on the e-invoicing readiness of customers and suppliers.

New draft law on B2B e-invoicing mandate

The new draft law on the B2B e-invoicing mandate had been anticipated, as changes were needed to bring the Belgian VAT legislation more in line with the upcoming European Union (EU) VAT in the Digital Age (ViDA) changes (2030) and, in particular, to formally clarify that the Belgian B2B mandate only applies to Belgian-established taxpayers. The draft law also provides insight into situations involving fixed establishments and taxpayers in the agricultural sector.

However, the draft also includes an unexpected development. According to the currently published FAQ, the response to the question "What should I do if my customer is not ready to receive invoices via PEPPOL [the Pan-European Public Procurement On-Line system] on 1 January 2026?" suggested that suppliers could choose an alternative transfer method. Many understood this to mean that, although another channel could be used, the supplier would still be expected to issue a structured e-invoice (possibly accompanied by a paper or PDF copy). The new draft law now states that in such cases it is sufficient for the supplier to issue an invoice in a nonstructured format. In other words, a paper or PDF invoice would meet the supplier's legal obligations if the customer is not ready to receive e-invoices.

This is a significant update and one to monitor closely to see whether it remains in the final legislation once enacted. It is also important to understand that, unlike the tolerance period discussed above, changes proposed in the draft law are not time limited.

Implications

Both of these updates are expected to create situations whereby businesses will need to foresee multiple AR/AP processes as from 2026, depending on the e-invoicing readiness of their suppliers and customers. It will be important to have clear instructions for the organization's AP/AR teams and ensure clear understanding of the organization's rights and obligations vis-à-vis its counterparts.