Peppol invoice responses: what AP, RE, UQ and PD mean and what to do

A Peppol Invoice Response is a structured message in which the buyer tells the supplier what it decided about one invoice: received, under query, accepted, rejected or paid. It arrives after network delivery, it is not proof of payment, and buyers are not obliged to send one, so many invoices never get a response at all.

This guide covers both sides in OrdoGrid. If you sent the invoice, it shows where your client's response appears and what to do next. If you received the invoice, it shows which code to send. It does not cover technical send failures, shown as an Erreur (error) badge in Peppol → Outbox: for those, see fix a rejected or failed Peppol invoice. The Peppol pages are in French in every interface language, so labels are quoted as on screen with a translation in brackets.

Invoice Response

A Peppol business message from buyer to supplier, defined by Peppol BIS Invoice Response 3.2 as a UBL ApplicationResponse document and often still called IMR (Invoice Message Response). It carries a status code about one invoice or credit note and, where needed, a reason. It is separate from transport acknowledgements and from payment.

Delivered, answered, paid: three different signals

Providers also exchange a Message Level Status (MLS) about whether a document could be passed on. OpenPeppol requires providers to support it in stages up to early April 2027, and it replaces the older Message Level Response (MLR), which is to be fully retired on 1 May 2027. MLS is a delivery report between providers, not the buyer's decision.

Is anyone obliged to send or read Invoice Responses?

What we recommend. As a buyer, respond when it changes what the supplier will do: a question, a condition, a rejection. As a supplier, read every response, but let your bank account, not a response, decide when an invoice is paid. For anything that matters, also email or call, because not every provider or software package shows responses to its users.

The seven response codes and the order they follow

The specification sets these rules:

• Statuses advance in the order AB, IP, UQ, CA, RE, AP, PD. Any status can be the first one or be skipped, and UQ can be repeated. Anything that departs from this order is settled between the parties, outside Peppol.
• RE and PD are final (rule OP-BR111-R004). After AP, only PD may follow (OP-BR111-R005): a buyer cannot reject through Peppol an invoice it has approved.
• A response has no legal force and does not change the invoice (OP-BR111-R008, R009). Even a rejection does not free the buyer from its payment obligations (R011), and the supplier can dispute any status outside Peppol (R013).
• A response can carry a reason code from the OPStatusReason list, such as REF or PRI, a free text, and a requested action from the OPStatusAction list, such as provide information, issue a new invoice or credit fully.

If you sent the invoice: find your client's response in OrdoGrid

Responses travel over Peppol to your Peppol ID. OrdoGrid receives them only when it handles your reception (Mode : Envoi + réception on the Peppol page). In Mode : Envoi seul (send only), they go to whichever provider holds your Peppol registration for Invoice Responses, if any; if none does, they cannot reach you.

1. Open Peppol and the Récent or Inbox tab. When clients have answered, a blue banner such as 1 nouvelle réponse reçue (1 new response received) appears above the list. Despite its wording, it lists every response received, not only new ones.
2. Click the banner to expand it. Each line shows your invoice number, the status badge, the client's name, the date and time, and the client's note.
3. Click a line to open the sent invoice, or open it from the Outbox tab. The section Réponses reçues lists every response to that invoice with its badge, Note: (the client's text), De: (the client's name and VAT number) and the date and time. Hover over a badge to see its description.
4. To fetch new documents and responses at once instead of waiting for the automatic fetch, click Actualiser (refresh).
5. Act on the response as shown in the next section.

OrdoGrid shows the status and the client's note, but not the reason code or action code the client may have added. If the note does not say what the client expects, ask. A response never changes your invoice's status or balance: payments only count once you record them with Record payment, and corrections need a credit note.

If you sent the invoice: what to do with each response

To follow up a balance step by step, see follow up an invoice and record a partial payment.

After Rejetée: choose the correction by cause

Your invoice stays issued. OrdoGrid locks the amounts of an invoice sent on Peppol, and it allows a second send only after a technical error, so you cannot resend the same invoice to clear a rejection. A credit note that corrects a structured invoice must itself be structured and sent on Peppol (art. 53 §2bis VAT Code). Ask your accountant to confirm the VAT treatment whenever the rate, the VAT regime or the customer changes.

The full correction procedure is in correct, cancel or credit an issued invoice; what the structured credit note contains is in credit notes on Peppol.

If you received the invoice: send a response from OrdoGrid

Check the invoice first, as described in receive, check and answer supplier Peppol invoices. Then:

1. In Peppol → Inbox, click Répondre (reply) on the row, or in the opened document. The view Répondre à la facture opens.
2. Choose the Code de réponse (response code). Acceptée (AP) is preselected and marked Recommandé (recommended): change it unless you have finished checking and will pay.
3. For Rejetée, Acceptée conditionnellement and Sous question, choose a Code de raison (reason code) and write the Raison ou note (reason or note). OrdoGrid requires both.
4. Click Envoyer la réponse (send the response). The code appears in the document under Réponses envoyées (responses sent), with its transmission status. If that status shows an error, the response did not leave: tell the supplier by email instead.

The 14 reason codes in OrdoGrid's Code de raison list follow the Peppol list:

Do not use Répondre on a received credit note: OrdoGrid marks every response as referring to an invoice. If the credit note is wrong, contact the supplier directly.

Worked example: a query, an approval and a payment in two parts

Atelier Lumen SRL, a web studio in Namur, uses OrdoGrid in Mode : Envoi + réception. Its client Transports Meuse SA in Andenne checks every invoice against a purchase order and also answers through OrdoGrid. Invoice F-2026-0142 is issued on Tuesday 1 September 2026 and due on Thursday 1 October: website redesign €2,500.00 excluding VAT, VAT at 21% €525.00, total €3,025.00.

The two payments add up to the invoice: €1,000.00 + €2,025.00 = €3,025.00. On its side, Transports Meuse used Répondre three times: Sous question with Références incorrectes and its note on 3 September, Acceptée on 7 September, and Payée only after the second transfer on 1 October.

Had Transports Meuse rejected instead. With Rejetée (RE) and Références incorrectes on 3 September, the client would not process F-2026-0142 any further. Atelier Lumen would then issue credit note NC-2026-0018 for €3,025.00 (€2,500.00 + €525.00 VAT) referring to F-2026-0142, and a new invoice F-2026-0147 for the same €3,025.00 with PO 4500-2231 in N° bon de commande, both on Peppol. F-2026-0142 would show Annulée (fully credited) with nothing outstanding. For a missing reference, a query is usually the lighter route for both sides.

Edge cases and common mistakes

Evidence to keep

• As the supplier: OrdoGrid keeps each response under Réponses reçues on the sent document in Peppol → Outbox. File next to it your email answer to a query or condition, and the credit note and new invoice that follow a rejection. Invoices and credit notes must be kept for seven years from 1 January of the year after issue (art. 60 VAT Code).
• As the buyer: keep the supplier's invoice, your response under Réponses envoyées and the supplier's credit note together, and pass them to your accountant, for example with the bulk ZIP download from the Inbox, which contains the XML and PDF files.
• For both: OrdoGrid is not a legal archiving service and gives no retention guarantee, so keep your own copies.

FAQ

Does Traité mean my client accepted the invoice?

No. Traité only means that the invoice reached your client's Peppol provider. Acceptance is a separate Invoice Response, AP Acceptée, which the client may or may not send.

Does Payée mean the money has arrived?

No. PD means the client has initiated a payment, and with reason PPD it may be only part of the amount. Check your bank and record what arrived with Record payment; the response itself never changes your invoice's balance.

Can a client reject an invoice it has already accepted?

Not through Peppol: after AP, only PD may follow. If the client disputes the invoice afterwards, settle it directly, and issue a credit note only if you agree to change the invoice.

Is a Belgian business obliged to send Invoice Responses?

Not in general: the 2026 obligation is about issuing and receiving structured invoices, and responses are optional in standard Peppol. FPS Finance does ask you to reject an invoice not intended for you, for example with RE, and a buyer that receives invoices in the separate Billing with response profile must answer each one.

What should I do after a Rejetée?

Read the note, contact the client and find the cause. If the invoice itself must change, issue a credit note on Peppol and, if needed, a new invoice; if the reason is not valid under Belgian rules, explain that instead. Never resend the same invoice number.

Why do I see no responses in OrdoGrid?

Most often the client simply does not send them. Otherwise your company may be in Mode : Envoi seul, so responses go to the provider that holds your registration (if there is one), or they have not been fetched yet: click Actualiser.

How quickly should a buyer respond?

A buyer that uses Invoice Responses must send the first one within 3 working days of receiving the invoice. A supplier that hears nothing should wait those 3 working days before asking whether the invoice arrived.