Technical guide for NAV Online Invoice data reporting registration

From 1 July 2020, you are required to report data of all transactions between domestic taxpayers to NAV (NTCA, National Tax and Customs Administration of Hungary), regardless of the amount of VAT. Therefore you are required to report all invoices issued for enterprises.

The obligation to report invoices online is also valid for taxpayers who fall under the reverse charge mechanism and/or issue invoices regarding transactions that are exempt from VAT. The latest regulation is therefore valid for everyone, with the exception of:

  • issuing invoices to entities in foreign countries only
  • issuing invoices to individuals (natural persons) only

From 1 January 2021, all invoices with a domestic place of performance shall be reported – this also applies to invoices where the buyer is a natural person.

IMPORTANT: The registration in the NAV Online Invoice system and connecting Számlá with it are not the same as the obligation to report online invoicing programmes. If you have just started to use Számlá, you or your accountant must report using it to the tax authority via the ÁNYK software.

We show you how to register in the NAV Online Invoice System and connect your Számlá or MostSzámlázz account with the NAV system!

We present the connection of the systems in two videos:

Detailed introduction with live commentary by our colleague
Short video with screenshots and a description of the steps

Or read our step by step introduction with screenshots and read the instructions!

STEP 0/1 – Do you have governmental “Client Gateway” (Ügyfélkapu) access?

If you already have access, you may proceed to the next section (Step 1). However, if you do not have access yet, you need to request a “Client Gateway” (Ügyfélkapu) identifier. Any natural person can do this:

  • If your personal ID card was issued after 1 January 2016, you can request the identifier at the “Client Gate” (Ügyfélkapu) registration page by clicking on the “E-identifier” (E-személyi) button. Please click here to find the instructions for e-registration.
  •  If you are not eligible, you may request the client gate identifier personally in any office for government-issued documents (okmányiroda), government administration window (kormányablak), NAV central customer services, certain postal customer services or foreign missions.

If you request the client identifier (ügyfélazonosító), you get the identifier immediately. You just need to activate it.

STEP 0/2 – Activating the client gateway (ügyfélkapu)

After you have registered successfully, you will receive a single-use code for the first login sent by the system to the email address provided during the registration. You may use the single-use code received via email within 3 days after sending it. Click on the link sent in the email, and fill in the form on the “Activation” (Aktiválás) page. Click here for instructions.

If you have registered online with an electronic personal identification card (which you can do if your personal identification card was issued after 1 January 2016), once you have registered successfully, you may login to the space after about an hour using the password provided during registration.

For the registration you will need:

  • a client gateway (ügyfélkapu) username/password (one that your enterprise is assigned to)

  • tax identification number (that of the owner of the client gateway access).

  • name of enterprise

  • tax number of enterprise

  • registered seat

  • Számlá account login information (email address, password)

Do not get mixed up!

During the process of registration, you may get a little mixed up in the series of usernames and password. Let us make it clear: during the registration process, you will need login information for 4 systems in total (a part of which we are going to create together now):

  1. Client Gateway (Ügyfélkapu) username and password (you hopefully have it already)
  2. NAV Online Invoice system username and password (we are going to create this in the next steps)
  3. NAV Online Invoice system TECHNICAL user password (we are going to create this too)
  4. Számlá login information: email address and password (if you have registered, you may already have this, too)

It is important that the above mentioned usernames and passwords may be identical if you wish, but they do not need to be identical.


You are required to register in the NAV Online Invoice system via the website.


For the first time, please agree to the Privacy Policy and choose the “Registration by taxpayers obliged to supply data”  button.


Sign in via the Client Gateway (Ügyfélkapu)! IMPORTANT: You are required to use the login of the user (primary user) to whom the enterprise is assigned in the Client Gateway (Ügyfélkapu) System.


After you have signed in successfully, please provide your tax identification number. Click on “Verify data”.

To register in the NAV Online Invoice system, choose a new username that you would like to use. This can be the same as your Client Gateway (Ügyfélkapu) username if the system accepts it.


Choose the type of registration: “Business Organization” or “Private enterpreneur”. Click on the “Verify taxpayer data” button!


Provide all the necessary further information and the new password of your choice for the NAV Online Invoice system.


After successful registration, sign in with the username and password you have provided!


If the user has multiple Company-user relations, click on “Company-user relations” available from the drop-down menu located in the upper right corner.


If the user only has one Company-user relations, the application automatically proceeds to the “Company-user relations” page, where you have to click on the “Open” button next to the taxpayer information.

IMPORTANT: If the system has not redirected you to the screen shown in Step 10, click on the “Users” menu in the grey menu bar.


On the “Users” page, click on the “New user” button.


Create a new “Technical user”.


Provide a password of your choice, and check the “Manage invoices” and “Query invoices” checkboxes, then click on the “Save” button.


Click on the “Generate key” button on the screen to create the XML Signature Key and XML Exchange Key.


Sign in your Számlá account and type in the technical user name and password created in the NAV system, the XML Signature Key and the XML Exchange Key (4 pieces of data) in your invoicing account in the empty fields Beállítások/Fiók beállításai/NAV online adatkapcsolat (Settings/Account settings/NAV online data connection). ATTENTION: If you have accidentally completed the registration in the NAV test system, you cannot create a connection using the above-mentioned information. The creation of the connection can only be successful if you register in the live NAV system!


How do you know that your registration has been successful? After you have signed in, take a look at your NAV icon in the Vezérlőpult (Control Panel) by clicking on the house symbol in the top left-hand corner! Is it green? You did it!

Please try again if NAV’s system is temporarily unavailable.

Congratulations, you have created the connection successfully!