Plenty of invoices around Liège still come out of Excel. One file for invoices, another for stock “because the first one is never current”, reminders in Outlook, and on the 5th someone copies the lot across to the accountant. WinBooks, Sage BOB, Exact: it makes no difference which software sits on the other side. The source is still version_finale_v7.xlsx.
Until last year, a PDF sent by email did the job. Since 1 January 2026, between Belgian VAT-registered businesses, that is no longer really the case. The law of 6 February 2024 added § 2bis to Article 53 of the VAT Code: a structured e-invoice, meaning a file that software can read without anyone retyping it. The decree of 8 July 2025 points to Peppol BIS (UBL, EN 16931). You can agree on another EN 16931 channel; that does happen. You still need to be able to send and receive Peppol.
B2C is not covered. A customer abroad who is not on Peppol can still receive a PDF. It is Belgian B2B that has changed.
There was a grace period in the first quarter of 2026, until 31 March. Grant Thornton and EY are explicit: this was not a postponement of the law. After that, the tax administration can impose fines. The scale in Royal Decree no. 44 is €1,500, €3,000, then €5,000, with at least three months between two findings. As for how many fines have actually been issued, I have no public figure, so I do not quote one.
There is also a small safety valve, dating from 10 February 2026: if the recipient cannot receive a structured file, the issuer is not forced to send Peppol. They must still issue an invoice. That does not allow a customer to stay unreachable.
Hermes, at BOSA, used to convert structured invoices into PDFs for businesses with no software. PwC reported that it would close on 31 December 2025. It was handy while businesses got equipped.
We keep Excel. A budget, a scenario, a chart: those have no business being anywhere else. The trouble starts when the spreadsheet becomes the customer list and the invoicing channel.
That is where it goes wrong: no unique identifier (the BCE/KBO company number is not the VAT number, even though they look alike), 21/12/6% VAT typed by hand, stock in one place and invoices in another, reminders only in the mailbox, and the monthly re-keying for the accountant.
Peppol sends the invoice. Chasing late payment falls under the law of 2 August 2002: 30 days if the contract says nothing, interest from the day after the due date, and a €40 flat fee. I am not quoting the FPS commercial interest rate, because its page would not open.
Early-payment discounts (escompte) are another trap. In Belgium, VAT is calculated on the discounted amount, even if the customer does not take the discount. This is documented in Odoo Belgium. In a spreadsheet, people get it wrong and the VAT return no longer adds up.
Invoicing software
Search “invoicing software Belgian SME” in 2026 and one question is enough: does it send and receive Peppol BIS 3.0? Sage BOB, WinBooks, Exact Online, Odoo with the Belgian localisation (EAS 0208, company number, BIS Billing 3.0): yes. An 18-month SAP project: not for this.
Where to start, in practice: tidy up the records. One customer, one identifier: the company number in one field, the VAT number in another, and the name exactly as registered in the Crossroads Bank for Enterprises. If “Dupont SPRL” and “Dupont srl” sit in two different files, Peppol will send them very cleanly, and it will be wrong.
Then connect the tool: one test for sending an invoice, one for receiving. Then stop retyping everything for the accountant. If the same line goes from Excel to WinBooks, the work has already been done twice. Set the old workbooks to read-only and start from the customers who are still active. The new tool does not need fifteen years of history.
If the data mapping and Peppol take up your whole week, an hour pack on www.z80.be is made for exactly that. info@z80.be, +32 494 111 041.