eVAT M2M registration: the 6 steps to access

eVAT M2M access requires a technical user, a signature key and an exchange key, as well as permissions assigned across two interfaces. This guide presents the complete process in the correct order.

Which M2M registration do you need?

NAV operates two separate machine-to-machine channels with two separate registration processes. One does not replace the other.

• NAV M2M registration — Machine submission of forms and documents to NAV as an alternative to ÁNYK forms. NAV Customer Portal → M2M registration application. Authentication: API key.
• eVAT M2M registration — Machine submission of VAT returns through the eVAT system. NAV User Management → technical user. Authentication: signature and exchange keys.

I am setting up eVAT access

As a taxpayer or representative, you are setting up a technical user, keys and eVAT permissions for the submitting software.

Who can do this: The taxpayer’s primary user: the taxpayer itself, its legal representative or its permanent representative.

What this is for: Creates the technical user, key pair and operational permissions required for the eVAT M2M connection.

1. 1. Select the correct taxpayer

   NAV User Management — https://uam.nav.gov.hu/

   Before starting the configuration, sign in to the Online Invoice system at least once. This is required for the remaining functions to become available.

   Sign-in takes place through NAV User Management using KAÜ authentication. This is the shared entry point for Online Invoice, Online Invoicing and eVAT.

   If you are authorised to represent more than one taxpayer, select the organisation for which you are configuring the eVAT M2M connection.

   Result: The correct taxpayer profile is active and the Users (Felhasználók) menu is available.

   Important: The technical user, keys and permissions are created separately for each taxpayer. Before continuing, check that the correct organisation is selected.

2. 2. Create a technical user

   NAV User Management → Users (Felhasználók)

   In the Users menu, create at least one technical user for the taxpayer concerned.

   An existing Online Invoice technical user can also be used if it receives the necessary eVAT permissions. With a separate technical user, the permissions and keys of the two data connections can be clearly separated.

   Result: The technical user to which the keys and permissions are linked has been created.

   Important: Since 25 April 2024, user management has been available in NAV User Management, rather than in the Online Invoice interface.

3. 3. Generate a signature key and exchange key

   NAV User Management → Users → technical user

   The technical user requires two keys: a signature key and an exchange key. The M2M connection will not work without both.

   Generate both keys on the technical user’s profile, then transfer them securely for the submitting software’s configuration.

   Result: The key pair required for the submitting software to identify itself to NAV is available.

   Important: The eVAT signature and exchange keys are not the API key used for NAV M2M document submission. The two authentication methods are not interchangeable.

4. 4. Grant interface access permission

   NAV User Management → Users → technical user

   Permissions are configured at two levels and on two separate interfaces. First, in NAV User Management, grant the technical user the “Access to e-VAT system interface” permission — this allows access to eVAT at all. The technical user’s password can also be set here.

   Result: The technical user can access the eVAT interface; separate permissions are still needed for specific operations.

   Important: This permission alone is not sufficient. The next configuration must be completed in the eVAT web interface.

5. 5. Configure the eVAT permissions

   eVAT web interface → Users → technical user — https://eafa.nav.gov.hu/

   Use the Applications (Alkalmazások) function in NAV User Management to open the eVAT web interface. Open the Users (Felhasználók) menu, then select the technical user configured in the previous steps.

   Select the appropriate permissions for the tasks required: VAT return management, VAT return approval, and convenience services and queries.

   If the technical user was created automatically by the system for web XML upload, NAV states that this permission setting is not available for that user.

   Result: The technical user has the permissions required to perform the selected eVAT operations.

   Important: VAT return approval is a separate permission. Without it, the software can assemble and upload the return, but submission must be completed in the eVAT web interface.

6. 6. Enter the keys in your software

   The software submitting the VAT return

   Store the signature key and exchange key in the secure configuration of the software that submits the VAT return. The software then identifies itself to NAV on behalf of the technical user.

   Result: The access data are available; the connection can be checked in the test environment.

I am developing the interface

You are integrating the submitting software with the eVAT M2M interface and preparing the schemas, test environment and tax codes.

Who can do this: The developer performs the technical integration; representation rights are not required. The taxpayer’s primary user creates the technical user.

What this is for: Prepares the submitting system for the current eVAT schema, tax-code mapping and communication with the test environment.

1. 1. Get the specification and schemas

   NAV eVAT GitHub repository

   NAV’s eVAT GitHub repository contains the schema files, sample XML files and the current interface specification.

   Technical questions can be raised in the repository’s Discussions area. For legal-interpretation questions, use NAV’s official contact channel.

   Result: The schema and specification for the submitted file are available.

2. 2. Configure the test environment

   https://onlineszamla-test.nav.gov.hu/home

   The test environment is separate from production. A separate technical user and key pair must be created for each taxpayer.

   Test User Management is available at: https://uam-test.nav.gov.hu/

   Test-environment eVAT permissions are configured in the eVAT test interface: https://eafa-test.nav.gov.hu/home

   Important: Production-environment credentials cannot be used in the test system. If you have an access problem, NAV requests the taxpayer’s tax number, company name and the primary user’s tax identification code.

3. 3. Map your tax codes

   Create an unambiguous mapping between the source system’s tax codes and NAV standard tax codes. A correct technical connection does not replace accurate and consistent master data.

   Result: Your own tax codes are mapped to NAV standard tax codes.

4. 4. Implement against the current schema version

   The interface specification and schemas are versioned. Development must be based on the version currently designated as valid by NAV, and later version changes must be tracked in a controlled way.

The three stages of access

Configuration does not happen in a single interface. In NAV User Management (https://uam.nav.gov.hu/), the technical user and keys are created; the permissions for eVAT operations are then assigned in eVAT’s own interface (https://eafa.nav.gov.hu/).

Three permissions, three distinct task categories

NAV’s interface distinguishes three eVAT-specific permissions. The summary below is based on the operation list in eVAT M2M interface specification 2.0; for an individual permission question, the current NAV specification always takes precedence.

VAT return management

This allows your software to build and upload the return. The application uploads the VAT records and return data, manages attachments and finalises the upload process. Without it: Your software cannot upload the required data and therefore cannot assemble the VAT return through M2M. Relevant operations in the specification: ManageDeclarationUpload, ManageDeclarationPartition, ManageDeclarationFinalize, ManageAttachmentUpload, PurgeAttachment

VAT return approval

This allows the completed VAT return to be submitted through the M2M channel. NAV separates this permission from return assembly. Without it: The VAT return can be assembled and uploaded, but it cannot be submitted through the machine interface. Someone must approve it manually in the eVAT web interface. Relevant operations in the specification: ManageDeclarationSubmission

Convenience services and queries

This allows the processing status, previous returns and documents to be queried, as well as tax-code and customs data available from NAV. Without it: Submission may still work, but your application operates with limited visibility. It cannot retrieve processing statuses or make use of the relevant NAV data-query services. Relevant operations in the specification: QueryDeclarationProcessingStatus, QueryDeclarationList, QueryDeclarationData, QueryDocumentList, QueryAttachmentList, QueryTaxCodeCatalog, QueryInvoiceTaxCode, QueryCustomsDeclarationTaxCode, QueryCustomsDeclarationDigest

Typical problems and their direct solutions

• The connection belongs to the wrong taxpayer. The configuration was started from another taxpayer profile. The technical user, keys and permissions are created separately for each taxpayer.
• The interface is reachable, but operations cannot be performed. You granted only the first level, the interface-access permission. The eVAT permissions are not in User Management, but in eVAT’s own web interface.
• The eVAT permissions are not visible in User Management. These permissions are in eVAT’s own web interface. Use Applications (Alkalmazások) to open eVAT, then select the technical user.
• The Users menu cannot be found in Online Invoice. It moved to NAV User Management on 25 April 2024. NAV’s preparation guidance still refers to the old location.
• The VAT return is prepared, but M2M submission cannot be started. Approval is a separate permission — you enabled only VAT return management.
• Production access does not work in the test environment. The test environment is standalone. It requires a separate technical user and separate keys.
• The system rejects the NAV M2M API key. They are two separate systems with separate authentication. eVAT expects a signature key and exchange key; the API key belongs to NAV M2M document submission.

Sources and limitations

NAV’s earlier preparation guidance still refers to the Users menu in the Online Invoice system. However, NAV’s later announcement states that secondary and technical users have been managed in NAV User Management since 25 April 2024. This guide follows the newer guidance; if the interface changes, NAV’s current documentation takes precedence.

Separate access for the test environment

The test environment is a standalone system. Production access cannot be used there: create a separate technical user and a separate key pair. Test Online Invoice environment: https://onlineszamla-test.nav.gov.hu/home

Sources

• NAV — eVAT system user manual (PDF, Hungarian)
• NAV — eVAT documentation, specifications and tax codes
• NAV — answer on technical-user permissions (eVAT GitHub, #220)
• NAV — eVAT questions and answers
• NAV — Preparing to use eVAT
• NAV — New login interface: NAV User Management
• NAV — eVAT test environment announcement
• NAV — eVAT M2M interface specification 2.0 announcement
• NAV eVAT GitHub repository — schemas, examples and specifications

eVAT M2M guide

eVAT validation messages

NAV M2M registration