E-invoicing in Croatia: HR-CIUS, OIB, CPA codes
Since 1 January 2026 e-invoicing is mandatory in Croatia for domestic B2B transactions, together with real-time reporting of those invoices (Fiscalisation 2.0). The format is HR-CIUS, a profile of EN 16931. Two fields trip up almost every non-Croatian tool: the CPA code on every line, and the OIB of the person issuing the invoice.
Mandatory since 1.1.2026 for VAT-registered companies established in Croatia, domestic B2B, plus e-reporting. From 1.1.2027 more groups follow. Format: HR-CIUS (EN 16931, UBL 2.1 or CII). Specifics: a CPA 2.1 code per line and the operator OIB with a MOD 11,10 check digit. Transmission runs through a certified intermediary. Vera produces the HR-CIUS file including CPA lookup and OIB validation.
Is e-invoicing mandatory in Croatia?
Yes. The Croatian Fiscalisation Act (Fiscalisation 2.0) requires structured e-invoicing and real-time reporting since 1 January 2026 for domestic B2B transactions between VAT-registered businesses established in Croatia. A test phase ran from 1 September 2025.
| Date | Obligation | Who |
|---|---|---|
| 1 Sep 2025 | Test phase | voluntary |
| 1 Jan 2026 | Issue, receive, report | VAT-registered companies established in HR (B2B) |
| 1 Jan 2027 | Extension | sole traders, liberal professions, non-VAT bodies |
Format and transmission
The format is HR-CIUS, a Croatian CIUS (Core Invoice Usage Specification) of EN 16931, in UBL 2.1 or UN/CEFACT CII. Transmission and reporting do not go directly to the authority but through an information intermediary certified by the Porezna uprava (tax administration).
The two Croatian gotchas
Beyond the EN 16931 mandatory fields, HR-CIUS requires two things that most non-Croatian tools miss.
| Field | Rule | Note |
|---|---|---|
| CPA code per line | HR-BR-25 | 6-digit CPA 2.1 code per item, e.g. 62.01.11. Missing code: rejection. |
| Operator name | HR-BR-9 | First and last name of the person who issued the invoice. |
| Operator OIB | HR-BR-37 | 11-digit OIB of the issuing person, with a valid MOD 11,10 check digit. |
| Buyer OIB | EndpointID | Scheme ID 9934 or 0217 for the company OIB. |
The OIB check digit follows the MOD 11,10 algorithm. Trying digits 1 to 9 is not enough, the real algorithm has to compute it, otherwise the number is rejected as invalid.
Common mistakes
- CPA code missing: without the per-line code the validation rejects. Vera suggests three likely codes with descriptions for a given activity.
- Operator not captured: without the issuing person's name and OIB there is no pass.
- OIB checked for format only: an 11-digit number without the correct MOD 11,10 digit is rejected.
- No intermediary connected: the file is valid but sending and reporting are missing. Generation and transmission are two steps.
FAQ
When does e-invoicing become mandatory in Croatia?
Since 1 January 2026 for VAT-registered companies established in Croatia, domestic B2B, including real-time reporting. From 1 January 2027 more groups such as sole traders follow.
Which format does Croatia use?
HR-CIUS, a Croatian profile of EN 16931, in UBL 2.1 or CII.
What is the CPA code and why does every line need one?
The CPA 2.1 code classifies the service statistically, e.g. 62.01.11 for computer programming. HR-CIUS requires it per line, otherwise the invoice is rejected.
What is the operator OIB?
Beyond the company, the issuing person must be shown, with name and 11-digit OIB, which must carry a valid MOD 11,10 check digit.
Does Vera transmit the invoice to the Croatian tax administration?
No. Vera produces the HR-CIUS file with OIB and CPA codes and validates it. Sending and reporting run through a certified intermediary you need in addition.
HR-CIUS with CPA and OIB from the browser
Vera produces the HR-CIUS file to EN 16931, with a CPA lookup per line and a MOD 11,10-checked OIB, validated before download. You connect the intermediary for transmission and reporting afterwards.
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