E-Invoicing in Croatia: Fiscalization 2.0, HR-FISK & Compliance Explained

E-Invoicing in Croatia

Croatia’s new Fiscalization Act, commonly referred to as “Fiscalization 2.0”, introduces a mandatory e-invoicing and real-time e-reporting regime for domestic transactions, including B2B (business-to-business) and B2G (business-to-government). The reform is designed to improve fiscal transparency, streamline tax compliance, reduce invoicing errors, and drive the digital transformation of business accounting processes. 

From 1 January 2026, VAT-registered companies must both issue and receive structured e-invoices, while non-VAT-registered entities must be ready to receive them. By 1 January 2027, non-VAT-registered entities will also have to issue e-invoices. This blog explains the requirements in Croatia, the accepted technical standards, key deadlines, who must comply, system integration, validation rules, the benefits, and how Flick Network can support businesses in making the switch smoothly.

What Is E-Invoicing in Croatia

In Croatia, “e-invoicing” under the Fiscalization 2.0 regime refers to the electronic issuance, transmission, receipt, and real-time tax reporting, also known as continuous transaction control (CTC), of structured invoice data. The system is part of a broader reform that extends fiscalization beyond cash-based B2C transactions to include B2B and B2G. The goal is to capture detailed invoice-level data almost instantly, improving the accuracy of tax reporting.

An electronic invoice under this system must comply with the European standard EN 16931-1:2017, along with additional local technical specifications defined by the Croatian Tax Administration. Unlike a simple PDF, Croatia requires structured data. Mandatory invoice fields include supplier and buyer information, tax base, VAT, payment terms, the supplier’s bank account number, product classification codes (KPD), and a digital signature linked to the issuer’s OIB (tax ID).

Fiscalization is essential. Each time an invoice is issued or received, the data must be reported, or fiscalized, to the Tax Authority, using certified intermediary service providers. In addition to e-invoicing, there are e-reporting obligations in real-time. This includes invoice issued, invoice received, payments made, rejections of invoices and situations where you cannot issue an invoice, such as if the recipient of the invoice is not registered in the e-invoice directory.

Key Deadlines and Requirements

Here’s the corrected and precise timeline:

• 1 September 2025: The Fiscalization Act enters into force. A testing phase, also called the sandbox, begins for businesses and information intermediaries to test e-invoice exchange, fiscalization, and reporting.

• 1 January 2026: Mandatory issuance and receipt of e-invoices for VAT-registered businesses begins, along with real-time reporting, also known as fiscalization.

• 1 January 2027: The obligation to issue e-invoices applies to non-VAT-registered entities, including small companies, freelancers, and public bodies.

Scope and Exemptions

Here’s who is covered and what the regime includes:

• B2B (business to business): All domestic transactions between VAT-registered taxpayers must be e-invoiced under Fiscalization 2.0.

• B2G (business to government): Already under e-invoicing through Servis eRačun za državu, now with added real-time reporting obligations.

• Non-VAT entities: Must receive e-invoices from 1 January 2026 and must issue them from 1 January 2027.

• B2C (business to consumer): Every sale, regardless of payment method, is subject to e-reporting or fiscalization from 1 January 2026.

• Exemptions or special cases: Paper invoices are allowed only in limited and exceptional situations, for example when the recipient’s e-invoice address is not registered in the AMS directory.

Technical and Validation Rules

To comply with Fiscalization 2.0, businesses must follow several technical and operational rules:

1. Standard: E-invoices must conform to EN 16931-1:2017. Croatia uses a local CIUS (Core Invoice Usage Specification) extension, called HR-FISK 2.0, in UBL 2.1 format.

2. Information Intermediaries and Access Points: Invoice exchange happens through certified access points or information intermediaries that are registered in a national directory called AMS.

3. Transmission Protocols: Secure communication protocols such as AS4 and Peppol are supported by intermediaries.

4. Digital Signature: Fiscalization messages must be digitally signed with a qualified certificate that includes the issuer’s OIB.

5. Fiscalization Time: Recipients have 5 working days to fiscalize received invoices.

6. Reporting: E-reporting includes invoice issuance, invoice receipt, payments, rejections, and failures to issue an invoice due to a missing AMS address.

7. Archiving: E-invoices must be stored for 11 years.

Benefits of E-Invoicing in Croatia

The reform offers several key benefits:

• Effectiveness: Automating the issuance, transmitting and reporting of invoices in real-time will help minimize the manual work required.

• Precision: Structured data minimizes the possibility of data-entry mistakes.

• Compliance: Reporting in real-time, fiscalization and adhering to real-time reporting enhances compliance with VAT and tax laws.

• Cost reduction: Paper, physical storage and courier costs will be reduced.

• Transparency: It will provide visibility into the lifecycle of invoices by authorities and businesses, i.e., issued, received, paid.

• Tax compliance: Better transaction level data will assist the Tax Authority detect fraud and improve the integrity of the tax base.

How to Prepare for E-Invoicing in Croatia

Here are recommended steps businesses should take now:

1. Evaluate your systems: Ensure your ERP / billing software can create structured e-invoices (UBL 2.1 + Croatia CIUS) and connect to information intermediaries.

2. Train your staff: Get accounting and finance teams up to speed on fiscalization, required fields (KPD, OIB, bank account), digital certificates, and archiving.

3. Pilot or test: Use the sandbox from 1 September 2025 to test invoice exchange, fiscalization, and error handling.

4. Partner with experts: Work with a service provider like Flick Network that understands Croatia’s technical and legal specifications, can help you connect to AMS / certified access points, manage message flows and lifecycle.

5. Plan archival & audit readiness: Implement a digital archive that stores e-invoices for 11 years, and define processes to support tax audits or compliance reviews.

How Flick Network Helps Businesses with E-Invoicing in Croatia

Flick Network can support Croatian businesses in multiple ways:

• Generation of compliant invoices: Flick can generate invoices in UBL 2.1 + CIUS format, meeting Croatia’s technical spec.

• Integration with information intermediaries / AMS: Flick can connect your system with certified access points and the AMS directory.

• Full lifecycle management: Flick manages invoice statuses (issued, received, fiscalized, rejected), handles rejections, and ensures correct e-reporting to the Tax Authority.

• Digital archiving: Flick provides a secure archive solution, compliant with the 11-year retention requirement.

• Scalability: Flick’s platform can handle low to very high invoice volumes without performance issues.

• Ongoing support & updates: Flick keeps you up to date on regulatory changes, technical spec updates, and process improvements under Fiscalization 2.0.

Conclusion

In Croatia, e-invoicing under the Fiscalization 2.0 law is not optional. It is a mandatory, structured, real-time system for domestic B2B and B2G transactions. The regime uses EN 16931-based formats, digital signatures tied to OIB, secure transmission, and continuous reporting. The transition requires preparation, but the benefits such as transparency, efficiency, and compliance are significant. Businesses that act early will reduce risk, avoid disruption, and operate smoothly in this new digital fiscal environment. Flick Network is a reliable partner that helps companies integrate, comply, and grow in the e-invoicing era.

FAQs

1. What formats of e-invoices are acceptable in Croatia?

    Invoices must comply with EN 16931-1:2017, using UBL 2.1 with Croatia’s CIUS extension, also known as HR-FISK.

2. Are there exceptions to the e-invoicing requirement in Croatia?

    Yes. In limited domestic cases, paper invoices may still be used, for example when the recipient is not registered in the AMS directory.

3. What happens if a business does not comply?

    Non-compliance, for example failing to issue or receive e-invoices, failing to fiscalize on time, or using incorrect digital certificates, will lead to penalties.

4. How can Flick Network help with Croatia’s e-invoicing transition?

   Flick can integrate with your existing systems, generate compliant e-invoices, connect to certified access points and the AMS directory, manage fiscalization, and archive invoices securely. This helps you navigate the legal and technical requirements smoothly.