VAT-inclusive prices, discounts and rounding on Belgian invoices

Enter each price exactly as you agreed it: including or excluding VAT. For prices that include VAT, tick Prix unitaires TVAC (TVA incluse) (VAT-inclusive unit prices) before you type them. OrdoGrid's screens and PDFs use the Belgian abbreviations TVAC (TVA comprise, including VAT) and HTVA (hors TVA, excluding VAT), and so does this guide. OrdoGrid keeps each entered price exactly, derives net and VAT per rate, and shows any cent difference as a separate Rounding line (Arrondi in French) instead of changing your price.

This guide is for businesses and freelancers who invoice from VAT-inclusive prices or give discounts, and for accountants who check the totals. The full list of mandatory mentions is in Mandatory mentions on Belgian invoices: the 2026 checklist; which regime applies is in VAT regimes on Belgian invoices.

TVAC or HTVA: which price basis to enter

Each line remembers the basis in which its price was typed. The box is therefore not a converter: ticking it later changes the display, not what the customer pays.

What Belgian law requires, whichever basis you use

The law. A full invoice must show, for each VAT rate or exemption, the taxable amount, the unit price excluding VAT and any discounts, rebates or early-payment reductions not included in the unit price, plus the VAT rates and the total VAT (Royal Decree no. 1, art. 5 §1, 8° and 9°). A full invoice showing only VAT-inclusive unit prices does not meet point 8°. As far as amounts go, a simplified invoice (art. 13: allowed for example up to €100 excluding VAT, but not for exempt intra-EU supplies of goods or reverse-charge supplies) needs only the taxable amount per rate and the total VAT, not unit prices; in-scope B2B simplified invoices must still be sent as structured invoices.

Royal Decree no. 8 rounds VAT to the cent. Since 1 January 2026, structured e-invoices issued under the B2B obligation follow the rounding rules of the EN 16931 standard instead (RD no. 8, art. 1, fourth paragraph, inserted by the Royal Decree of 17 December 2025). Peppol BIS Billing rounds each line net amount to two decimals, calculates VAT per rate and allows a rounding amount (BT-114) that is added to the amount due (BIS chapters 9 and 10). For in-scope B2B invoices, the structured invoice has been the legal invoice since 1 January 2026; a PDF copy is optional.

What OrdoGrid prints.

PDF labels follow Profil entreprise → Langue des documents (company profile → document language); English documents read Price incl. VAT, Rounding, Total incl. VAT and Amount payable. Sous-total HTVA is the net amount before discounts, so the total taxable amount is Sous-total HTVA minus Total des réductions. On the PDF, Total TVAC (Total incl. VAT on English documents) already includes the rounding: €138.00 in the example below. In the XML, the total including VAT (BT-112) is the legal €137.99, and the rounding is added only in the amount due (BT-115).

How OrdoGrid turns VAT-inclusive prices into net, VAT and rounding

1. It keeps the unit price you typed, with all its decimals, and its basis.
2. Each line net amount is quantity × price including VAT ÷ (1 + VAT rate), rounded to the cent.
3. Net amounts are added per VAT rate, and VAT is calculated once per rate, rounded to the cent.
4. The agreed amount is quantity × price including VAT per line, rounded to the cent, minus discounts.
5. The difference between the agreed amount and net plus VAT is the rounding amount. Montant à payer (amount payable) is net plus VAT plus rounding, minus any prepayments.

Rounding amount

The positive or negative difference between the amount payable based on your VAT-inclusive prices and the legal total of net plus VAT. It is neither taxable amount nor VAT. In Peppol it is the PayableRoundingAmount, BT-114.

Worked example: why the customer pays €138.00, not €137.99

Fietsen Peeters BV in Leuven sells bike lights from its shop price list to Snelkoeriers Gent BV. Invoice F-2026-0042, dated 12 October 2026 and due on 11 November 2026, has two lines at 21% VAT:

• Net per line: 6 × €11.50 ÷ 1.21 = €57.0248, rounded to €57.02.
• Net total €114.04; VAT €114.04 × 21% = €23.9484, rounded to €23.95.
• Legal total including VAT: €114.04 + €23.95 = €137.99.
• Agreed amount €138.00, so the rounding is +€0.01 and Montant à payer is €138.00.

Calculating VAT per line (€11.97 + €11.97) would give €137.98. Working back from €138.00 as one amount would give €114.05 net, but EN 16931 rounds each line net amount first. The unit price excluding VAT is €9.504132…: the XML carries it in full, while a PDF in HTVA display prints €9.50, so 6 × €9.50 next to €57.02 is expected.

The rounding can also be negative: one item at €0.14 including 21% VAT gives €0.12 net + €0.03 VAT = €0.15, so the rounding is −€0.01. It is usually a cent or two, and can reach a few cents on invoices with many VAT-inclusive lines, because each line is rounded separately.

Switching the display, editing prices and changing the rate

• Ticking or unticking the box keeps every price, quantity and discount. Unit prices and line amounts switch between including and excluding VAT, and the last column header between HTVA and TVAC. Totals do not change.
• Editing a price gives the line the basis currently displayed. Typing €11.50 while the display is HTVA prices the line at €11.50 excluding VAT: six units then cost the customer €83.49 instead of €69.00.
• Changing a line's VAT rate keeps the entered price. On a TVAC line the customer price stays and the net changes: 6 × €11.50 at 6% gives €65.09 net + €3.91 VAT = €69.00. On an HTVA line the net stays.
• Mixing bases on one document is possible. We recommend one basis per document so that the customer can follow it.

Enter a VAT-inclusive invoice in OrdoGrid

1. Open Invoices (page Factures), click Nouvelle facture (New invoice) and choose the customer with Sélectionner un client.
2. In the Récapitulatif (Summary) sidebar, under Totaux (Totals), tick Prix unitaires TVAC (TVA incluse). On a small screen, open the sidebar first.
3. Click Ajouter un article and fill in Description, Quantité, Prix Unitaire (including VAT) and TVA (21% by default).
4. Add discounts if needed (next section).
5. Check Totaux: Sous-total, Total des réductions, TVA, Rounding (shown only when not zero; Arrondi in a French interface and on French-language PDFs) and Total TVAC.
6. Click Aperçu du PDF (PDF preview). If the PDF will be the legal invoice, untick the box first.
7. Click Enregistrer (Save), or Envoyer (Send) and then Sauvegarder & Envoyer (Save & Send). For Peppol, make sure Envoi électronique via Peppol (send electronically via Peppol) is ticked in the send popover.

Once a payment is recorded or the invoice is prepared or sent on Peppol, its amounts are locked; correct them with a credit note (correct or credit an invoice). Quotes, receipts, payment requests and credit notes have the same box, and Convertir en facture, Dupliquer and a credit note started from an invoice copy the prices, their basis and the box setting.

Discounts: per line or per document, percentage or amount

• Per line: click the tag icon on the line (tooltip Ajouter une réduction) and fill in the Réduction d'article row. On a phone, open the line and use Remise.
• Per document: click Ajouter une réduction under the totals; the Réduction globale bar appears, and Supprimer removes it.

Each discount is % or a fixed euro amount marked TVAC or HTVA; a fixed amount takes the basis displayed when you type it.

Percentages are limited to 0–100%, and a discount never exceeds the amount it applies to. On the PDF each discount appears under its line in the display basis, while Total des réductions is always excluding VAT. In Peppol, the line discount and the line share of a document discount travel as one allowance per line (BG-27, reason ‘Discount’); OrdoGrid sends no document-level allowance (BG-20). Before delivery, the XML is checked against the official rules, such as PEPPOL-EN16931-R120 on line net amounts (0.02 tolerance).

Example: the same €5 discount, two outcomes

Invoice F-2026-0042 with a document discount:

With €5.00 TVAC, each line gets €2.50 off its VAT-inclusive amount, or €2.07 net (€2.50 ÷ 1.21, rounded). That is why the PDF shows −€2.50 under each line but €4.14 in Total des réductions.

Early-payment discounts. OrdoGrid has no conditional discount for early payment: a discount you enter reduces the invoice at once. Royal Decree no. 1 lists early-payment reductions among the discounts an invoice must show when they are not in the unit price. Before you offer one, agree with your accountant how to treat the VAT base, since the customer may or may not take the discount.

Payments, credit notes and older invoices

• Payments. The SEPA QR code, a Lien de paiement (payment link), the Settlement panel (Invoice total, Outstanding) and Record payment use the amount payable including rounding: €138.00 here. If the customer pays €137.99, the invoice shows Partiellement payée (partially paid) with €0.01 outstanding; agree with your accountant how to clear such differences.
• Credit notes. A credit note started from the invoice copies its lines, prices, basis and document discount; total credits cannot exceed the invoice amount payable. Crediting the returned rear lights gives €57.02 + €11.97 VAT + €0.01 rounding = €69.00; crediting both lines brings credits to €138.00, and the invoice shows Annulée (cancelled).
• Older documents. Documents created before OrdoGrid stored VAT-inclusive prices keep their original calculation; issued PDFs and Peppol XML are never recalculated. An older invoice may show €68.99 for 6 × €11.50 and no rounding line. Editing an older draft recalculates it with the current method, but its lines stay net-priced: retype each unit price with Prix unitaires TVAC (TVA incluse) ticked to store it as a VAT-inclusive price (6 × €11.50 then gives €69.00).

Mistakes to avoid

Evidence to keep

• The price list, quote or order confirmation showing whether prices and discounts include VAT.
• The issued PDF: Original document in the Settlement panel keeps it unchanged.
• For Peppol invoices, the XML: Peppol → Outbox → download XML, or select rows for a ZIP with XML and PDF. OrdoGrid archives the exact XML it sent.
• Payment and refund records from the Settlement panel.

Invoices must be kept for 7 years from 1 January of the year after issue (VAT Code art. 60, as amended by the Law of 18 December 2025); documents linked to VAT revision on immovable property must be kept longer, as explained in invoice archiving. OrdoGrid is not a legal archiving service, so keep your own copies. See also invoice a month of freelance work for net-priced services, Peppol validation errors if a send is refused, and the public API for integrations.

FAQ

Why is there a €0.01 rounding line on my invoice?

Your VAT-inclusive prices add up to a different amount than the net total plus the VAT calculated per rate. OrdoGrid keeps the agreed price and shows the difference as a Rounding line (Arrondi on French documents). In the example, 2 × €69.00 = €138.00, while €114.04 + €23.95 = €137.99.

Can I remove the rounding line?

Not by hand: it follows from the prices. It disappears when net plus VAT equals the VAT-inclusive amounts, or when you price excluding VAT, in which case the customer pays exactly net plus VAT, often not a round amount.

Does the rounding change the VAT I owe?

No. VAT is calculated on the net amounts per rate; the rounding amount is outside the taxable amount and the VAT and only adjusts the amount payable. Ask your accountant which account to book it on.

Will my customer's Peppol software accept a rounding amount?

BT-114 is part of EN 16931, and rule BR-CO-16 checks that the amount due equals the total including VAT minus prepayments plus rounding. OrdoGrid validates the XML against these rules before delivery. If the customer sees a one-cent difference, point it to BT-114.

Why does an older invoice show €68.99 for 6 × €11.50?

Documents created before OrdoGrid stored VAT-inclusive prices keep their original calculation, which first converted the price to a net price. They are not changed retroactively; correct an issued invoice with a credit note. On an older draft, retype the unit prices with the box ticked.

Why does my €5 discount show as €4.14 in the totals?

Total des réductions is always excluding VAT. A €5.00 TVAC discount on two 21% lines is €2.50 per line including VAT, or €2.07 net per line: €4.14 in total.