Croatia: The Upgraded Application Enters Testing in October 2026 Ahead of the 1 January 2027 E-Invoice Issuing Duty for Taxpayers Outside the VAT System

KGT Country Update | 2 October 2026 | VAT, e-invoicing and SAF-T monitor

In a notice published on 2 September 2026, the Croatian Tax Administration (Porezna uprava) announced that an upgraded version of its free MIKROeRAČUN application, which will add e-invoice issuance, will be available for testing during October 2026. The upgrade serves the taxpayers who are not in the VAT system and who must begin issuing e-invoices from 1 January 2027.

The notice is a readiness and tooling announcement rather than a new legal act, and it falls within the October testing window that is now open.

Background

Croatia’s Fiscalization 2.0 regime introduced e-invoicing and its fiscalization through the Tax Administration’s system for VAT-registered taxpayers. MIKROeRAČUN is the tax administration's free application for small taxpayers. Until now it has allowed users to receive, review, search, reject, and store e-invoices, and to fiscalize the receipt or rejection through the ePorezna portal.

The Legislative Change

There is no legislative change in this notice. The obligation for taxpayers not registered in the VAT system to issue e-invoices from 1 January 2027 is referred to as an existing obligation; the notice does not cite the provision, and we have not resolved it in this run. The upgrade operates within that framework.

It is relevant in practice because it is the Tax Administration’s own route to compliance for small taxpayers and will define what the smallest suppliers in a supply chain can send.

Scope

• Users. Taxpayers not in the VAT system, including small businesses and sole traders, who from 1 January 2027 must issue e-invoices.

• Functionality. The upgraded application adds e-invoice issuance and the associated compliance functions without requiring additional IT solutions or additional cost, according to the Tax Administration.

• Existing functions retained. Receipt, review, search, rejection and storage of e-invoices, with fiscalization of receipt or rejection through ePorezna.

• Support materials. Educational materials and user guides are to be published on the Tax Administration’s website before the testing period.

Timeline

• 2 September 2026 — Tax Administration announces the upgrade.

• October 2026 — upgraded MIKROeRAČUN available for testing.

• 1 January 2027 — taxpayers not in the VAT system must begin issuing e-invoices.

Businesses Affected

Directly affected are small taxpayers outside the VAT system. Indirectly, multinational groups and larger Croatian businesses that buy from such suppliers will start receiving e-invoices from them from 2027, probably through the Tax Administration’s own application rather than through a commercial access point. Groups should therefore expect a population of very small suppliers whose invoices arrive in the e-invoice system and whose master data and contact points are minimal.

Required Actions

• For groups with Croatian entities that buy from small suppliers, identify which vendors are outside the VAT system and inform them of the 2027 duty and the free application.

• Confirm that your inbound e-invoice process can receive invoices from suppliers using MIKROeRAČUN, including rejection and fiscalization of receipt.

• Small taxpayers should register for the October test and read the guides when they are published.

• Monitor the Tax Administration’s fiscalization pages for the testing instructions and any production release date.

Practical Implications

The announcement will move a long tail of small suppliers into structured invoicing at once on 1 January 2027. Buyers should expect higher inbound volumes, some data-quality problems, and a surge of rejections in the first quarter. The fact that the application also handles receiving means some small recipients will fiscalize receipt themselves, which interacts with the buyer’s own processes.

Expected Next Steps

The Tax Administration is to publish user guides and educational materials before testing, and a production release is expected before 1 January 2027. KGT will report any technical specification changes or production dates when they are published.

How Can KGT Support You?

KGT delivers SAP-integrated e-invoicing add-ons and SAP Document and Reporting Compliance services for Croatia’s Fiscalization 2.0, including receipt, rejection, and fiscalization flows. We help groups prepare their accounts-payable processes for the surge of small-supplier e-invoices expected from 1 January 2027 and test connectivity against the Tax Administration’s environments.

This country update is provided for general information only and does not constitute tax, legal or professional advice.