MLR

What is a Peppol Message Level Response (MLR)?

⚠ Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.

Short answer

A Peppol Message Level Response (MLR) is a technical message by which the recipient’s system reports the result of processing an electronic message—for example, that it was received or could not be processed technically. MLR concerns the technical message layer, not the commercial content of the invoice, and does not mean that the invoice was approved.

Technical layer

Not commercial content

MLR informs about the processing of the message, not about the acceptance of the invoice.

Not approval

Does not apply to payment

MLR does not mean that the invoice has been paid or that the content is correct.

MLS as successor

Development of the standard

OpenPeppol sees Message Level Status as an evolution of the original MLR.

Recommended archiving

Part of the audit trail

If the MLR is created, it belongs to the invoice lifecycle documentation.

Detailed explanation

MLR must not be confused with Invoice Response, which provides information on the commercial status of an invoice (received, accepted, rejected). MLR forms part of OpenPeppol certification; according to available OpenPeppol documentation, the 5-corner model architecture treats MLS (Message Level Status) as a development of the original MLR, whilst MLR is still used in certain isolated scenarios. If an MLR or MLS is generated in a specific implementation, it is recommended that it be archived alongside the original e-invoice as part of the audit trail.

As stipulated by law and technical specifications

The use of MLR is not generally required by law — it depends on the implementation of the specific Access Point and on whether OpenPeppol requires it for the relevant certification. The VAT Act (Section 71(3)) requires that the authenticity of the origin, the integrity of the content and the legibility of the invoice be ensured — the MLR may be one of the technical records that contribute to this, but it is not the only option.

Practical examples

  • The recipient’s Access Point returns the MLR with a message stating that the message could not be processed due to an invalid format.
  • The sender’s system records a successful MLR as proof of technical delivery.
  • The company archives the MLR together with the original XML in case of a subsequent dispute regarding delivery.

Common misconceptions

  • “An MLR means that the recipient has approved the invoice.” No, the MLR relates solely to the technical processing of the message.
  • “An MLR is the same as an Invoice Response.” No, an Invoice Response describes the commercial status of the invoice, whilst an MLR describes the technical status of the message.
  • “MLR replaces the technical delivery confirmation.” No, it is a separate record type used in Peppol communication.

Conclusion

MLR confirms technical message processing in Peppol; it is neither a commercial decision on the invoice nor a substitute for Invoice Response.

Legal and technical basis

  • OpenPeppol Message Level Response Specification and Transport Infrastructure Agreements (TIA)
  • OpenPeppol BIS Billing 3.0
  • Act No. 222/2004 Coll. on VAT, Section 71(3)

Related questions

This does not constitute legal advice. Sources: Act No. 222/2004 Coll. on VAT, official methodological and information materials from the Slovak Financial Administration on e-invoicing, EN 16931, OASIS UBL 2.1, UN/CEFACT CII and OpenPeppol BIS Billing 3.0 documentation. Verified on 9 July 2026.