Understanding Message Level Status (MLS) in UAE e-Invoicing | PEPPOL Compliance Guide 2026

The UAE has a mandatory e-invoicing system that uses the PEPPOL framework to ensure standardized, secure, and efficient invoice exchanges.

A critical component, the Message Level Status (MLS), acts like a digital receipt, confirming whether an electronic invoice has been processed successfully or rejected due to errors. This helps businesses stay compliant with the Federal Tax Authority (FTA) and resolve issues quickly.

The PEPPOL Framework in the UAE

PEPPOL is an international framework designed to standardize the exchange of electronic business documents, such as invoices, orders, and catalogs.

It ensures interoperability across different systems and countries, making it easier for businesses to engage in cross-border trade.

The UAE has adopted the PEPPOL Decentralized Continuous Transaction Controls and Exchange (DCTCE) model, also known as the 5-Corner Model, to structure its e-invoicing system.

This model involves five key participants:

The UAE uses the PINT AE format, a localized version of the PEPPOL standard, to meet specific regulatory requirements and enable real-time tax data reporting to the FTA.

Understanding Message Level Status (MLS)

Message Level Status (MLS) is a critical component of the PEPPOL framework that provides acknowledgment of the processing status of an electronic document.

In the UAE?s e-invoicing system, MLS is sent from the buyer?s service provider (C3) to the supplier?s service provider (C2) to confirm whether an e-invoice has been accepted, forwarded to the buyer, or rejected due to errors.

According to the PEPPOL MLS Specification, MLS supports service providers in responding with the processing status of a business document, ensuring transparency and efficiency in the exchange process.

MLS messages are structured in XML format, adhering to the Universal Business Language (UBL) 2.1 standard, and include key elements such as:

• Status Code: Indicates the outcome (e.g., Accepted, Rejected).
• Document Reference: Links the MLS to the original e-invoice using a unique identifier.
• Description: Provides details, especially for rejections, to explain the issue.

The possible MLS statuses in the UAE context, based on the PEPPOL framework, include:

• Accepted without confirmation of forwarding (AB): The e-invoice is validated by C3 but not yet confirmed as forwarded to C4.
• Accepted with confirmation of forwarding (AP): The e-invoice is validated and successfully forwarded to C4.
• Rejected (RE): The e-invoice fails validation due to errors, such as incorrect data or format issues.

How MLS Works in the UAE?s E-Invoicing System

The process, as outlined by the UAE Ministry of Finance, follows these steps:

1. Invoice Submission: The supplier (C1) submits the e-invoice in the PINT AE format to their accredited service provider (C2).
2. Validation and Conversion: C2 validates the e-invoice against the UAE data dictionary and converts it to the standard XML format if necessary.
3. Transmission and Reporting: C2 sends the e-invoice to the buyer?s service provider (C3) and simultaneously reports a Tax Data Document (TDD), a subset of invoice data, to the FTA (C5).
4. Validation by C3: C3 validates the e-invoice and sends an MLS to C2, indicating one of the statuses (AB, AP, or RE).
5. Forwarding to Buyer: If validation is successful, C3 forwards the e-invoice to the buyer (C4) and reports the TDD to C5.
6. Handling Rejections: If validation fails, C3 sends a negative MLS (RE) to C2 and C5, and no TDD is reported by C3.
7. FTA Confirmation: The FTA (C5) sends an MLS to both C2 and C3 to confirm the TDD?s status.
8. Notification to Parties: C2 and C3 forward the relevant MLS to the supplier (C1) and buyer (C4), respectively.

This process ensures that all parties are informed about the invoice?s status, promoting transparency and accountability.

The MLS message is one-directional (from C3 to C2) and adheres to strict rules, such as sending only one MLS per document and not responding to other MLS messages.

Technical Aspects of MLS

MLS messages are implemented as XML documents using the UBL Application Response 2.1 schema, with specific namespaces for common aggregate and basic components. Key technical elements include:

• CustomizationID: urn:peppol:edec:mls:1.0, identifying the MLS transaction.
• ProfileID: urn:peppol:edec:mls, specifying the process profile.
• ResponseCode: Mandatory code indicating the status (e.g., AB, AP, RE).
• DocumentReference: Links to the original e-invoice?s unique identifier.
• MLS_TO and MLS_TYPE: Extensions allowing alternative addressing and control over response types (e.g., FAILURE_ONLY for RE only, or ALWAYS_SEND for all statuses).

For rejections (RE), additional details like StatusReasonCode (e.g., BV for business rule violation) and a description in English are included to clarify the issue.

These technical specifications ensure that MLS messages are standardized and interoperable across the PEPPOL network.

Benefits of MLS for UAE Businesses

• Real-time Feedback: MLS provides immediate confirmation of an invoice?s status, enabling businesses to address issues promptly.
• Error Reduction: By highlighting validation errors, MLS helps businesses correct mistakes, minimizing delays in payments or compliance issues.
• Enhanced Tax Compliance: Direct reporting of the TDD to the FTA ensures that transactions are monitored in near real-time, reducing tax evasion risks and simplifying audits.
• Global Interoperability: As part of the PEPPOL framework, MLS aligns the UAE with international standards, facilitating smoother cross-border transactions.

Preparing for the Change

To comply with the UAE?s e-invoicing mandate, businesses should take the following steps:

1. Partner with Accredited Service Provider: Select a PEPPOL-accredited provider, to handle e-invoice submissions and MLS processing.
2. Update Invoicing Systems: Ensure systems are compatible with the PINT AE format and can generate and process MLS messages.
3. Review Technical Documentation: Access the PASR, PINT AE, and UAE data dictionary via the Ministry of Finance e-invoicing portal to understand compliance requirements.

In conclusion, the MLS is a vital part of the UAE's new e-invoicing system, set to launch in July 2026. It provides real-time feedback on whether an e-invoice is accepted or rejected, helping businesses ensure compliance and efficiency.

Businesses should start preparing now by understanding MLS and working with accredited service providers.

For more details on how to navigate this change, you can contact our e-Invoicing experts (UAE e-Invoicing).