Digital signature in Hungary: why is it mandatory for every company?

Hungarian legislation is clear: a company cannot operate effectively without a digital signature. As of 2018, all companies must submit invoice data in real-time via the NAV Online Számla system. Without a qualified electronic signature (e-Szignó), this is technically impossible. The NAV system, the Ügyfélkapu portal, and Cégkapu all require authentication via e-Szignó. Without it, a company cannot file tax returns, transmit invoice data, or sign contracts with business partners. Failure to comply with these requirements not only hinders operations but also leads to legal consequences. In this article, we explain why a digital signature is a mandatory tool for every company registered in Hungary, how to obtain it, and what risks are associated with not having one.

What is a digital signature in Hungary?

In Hungary, a digital signature known as e-Szignó refers to a qualified electronic signature that complies with the requirements of EU Regulation No. 910/2014 (eIDAS). According to Article 25(2) of the eIDAS Regulation, such a signature has the same legal effect as a handwritten one. This means that documents signed using e-Szignó are legally valid and can be used in both official and commercial contexts.

Hungarian legislation, including the Civil Code (Act V of 2013), recognizes electronically signed documents using a qualified signature as written documents with full evidentiary value.

Companies in Hungary are required to use e-Szignó for a range of operations, including submitting tax reports through the NAV system, registering and updating corporate information via Cégkapu, and signing contracts and other legally binding documents.

Legal requirements for companies

According to Section 9 of Act V of 2006 on Business Associations and Section 6 of Act LXVI of 2016 on Electronic Administration, all legally significant actions performed via official digital platforms must be executed using a qualified electronic signature. This means that even basic filings—such as financial reports, notices of director changes, or amendments to the articles of association—require a valid e-Szignó.

Since 2017, registration with the Cégkapu (Company Gateway) system has been mandatory for all companies. Under Government Decree No. 451/2016 (XII.19), access to Cégkapu is only possible through an authorized representative using a qualified electronic signature.

When the use of e-signatures is mandatory

A qualified electronic signature is required in the following cases:

1. Signing and submitting the company’s annual financial statements to NAV;
2. Registering or updating company data through the Cégkapu portal;
3. Signing contracts submitted to government authorities;
4. Receiving or submitting official notifications via Ügyfélkapu (for individuals) and Cégkapu (for companies);
5. Representing the company in court proceedings—civil or administrative—through the Bíróság.hu portal.

In these processes, the use of a simple electronic signature (such as a scanned handwritten signature) is not permitted and is considered legally invalid.

Consequences of not having a digital signature

Failure to comply with the requirements for using e-Szignó may result in financial penalties and legal consequences. Companies may face fines for non-compliance with statutory obligations, restricted access to government systems, and legal disputes due to the invalidity of unsigned or improperly signed documents. In addition, the absence of a digital signature can complicate or even prevent participation in public tenders and other official procedures.

How a digital signature ensures the legal validity of documents

For an electronic document to be considered legally valid in Hungary, it must meet the following requirements:

1. Identification of the signatory: the document must contain information that identifies the person who signed it.
2. Resistance to modification: once signed, the document must not be altered without the ability to detect such changes.
3. Timestamp: It is possible to determine the exact time the document was signed.

How Key2Law can support your company with e-signature compliance in Hungary

The Key2Law team provides comprehensive support to companies that are required to use a qualified electronic signature in Hungary. We help you identify exactly who within your organization must hold an e-Szignó and assist in building internal processes that comply with both Hungarian regulations and the EU’s eIDAS framework. Our goal is to eliminate risks and simplify the technical implementation of digital signatures into your business operations.

We support clients at every stage—from selecting a trusted service provider to obtaining the certificate and integrating the signature with government platforms. Given the strict formal requirements for submitted documents, we also advise on the proper use of e-Szignó in corporate document workflows and communication with public authorities.

Contact Key2Law today. We’ll help you establish a secure, legally compliant, and efficient digital document management system for your business in Hungary.