E-invoicing and fiscalisation
Getting ready for mandatory e-invoicing: choosing a provider, connecting your software, and a test run.
Moving to e-invoicing is more than signing with a provider. The software you invoice from has to produce the right format, the certificate has to be in place, and somebody has to send a test invoice before the obligation starts.
What the rules require
Since 1 January 2026, VAT-registered businesses in Croatia issue and receive invoices to other businesses as e-invoices, and the data from those invoices is fiscalised with the Tax Administration. Entities outside the VAT system have had to be able to receive e-invoices since then, and their obligation to issue them starts in 2027.
An e-invoice is not a PDF sent by email. It is a structured XML file that follows the European standard EN 16931, usually in UBL format, and it travels through an information intermediary. Payment data and rejected invoices are also reported to the Tax Administration, so part of the bookkeeping routine changes as well.
Three ways to connect
- A module in your accounting or ERP software: the software builds the XML itself and sends it through the intermediary its vendor works with. The least manual work, but it depends on the vendor having updated the software.
- The intermediary's web portal: invoices are typed in or uploaded by hand. Fine for a few invoices a month, impractical for more because the data gets entered twice.
- Your own API integration: for companies with in-house software or a web shop. The most flexible option, but it needs development and testing.
What we recommend and why
If your software already supports e-invoicing, using that is almost always the best choice, because nothing is retyped and there is less room for error. We first check the software version and the master data: customer OIB numbers, tax categories, units of measure and payment methods, because those are the fields where invoice validation most often fails. Then we set up the certificate and the intermediary account, send a test invoice, and check that incoming invoices land where your bookkeeper expects them.
We recommend the portal only for sole traders and small companies with few invoices. Building your own integration makes sense when the software cannot do it and replacing the software would be a bigger job than the integration itself.
Common questions
Do I need e-invoicing as a flat-rate sole trader?
Flat-rate traders are mostly outside the VAT system, so since 2026 they have to be able to receive e-invoices, and issuing them becomes mandatory in 2027. Check the exact obligation for your case with your bookkeeper or the Tax Administration.
Does this apply to invoices for consumers?
No. The e-invoicing obligation covers invoices between businesses. Invoices to consumers are still fiscalised as before, through the cash register or invoicing software.
How much does the changeover cost?
It depends on the software you use and whether it already has an e-invoicing module. The intermediary charges for its service separately. After we look at your software you get a quote for the setup and the test run.