Mandatory e-invoice from January 1, 2027
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June 23, 2025
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Although January 2027 may seem far away, experience with other mandatory digitalization changes shows that those who start preparing early will save themselves stress and additional costs. From this date, all VAT payers will be obliged to issue and receive invoices exclusively electronically via the new state Electronic Invoicing Information System (IS EFA).
Who does the new obligation apply to and why?
From 1 January 2027, issuing invoices exclusively in electronic form will be mandatory for every VAT payer – whether it is a large joint-stock company or a micro-firm. The law will also affect entrepreneurs who invoice public administration entities, such as municipalities, schools or state institutions. On the contrary, private individuals, end consumers in B2C relationships will remain outside this obligation. For non-VAT payers, voluntary entry into the system is expected first and only then, depending on the course of practice, with a possible extension of the obligation.
What exactly is meant by the term "e-invoice"?„
An electronic invoice will not just be a PDF attached to an email. It will be a structured data file in XML format that will have to pass through the Electronic Invoicing Information System (IS EFA). Only after the content has been verified and a unique invoice identification code (IDF) has been assigned will the document become officially valid. This process is reminiscent of today's tax filing via the Financial Administration portal, but it will go one step further: each invoice will be registered in a central database immediately after it is issued.
The e-invoice lifecycle step by step
First, the entrepreneur creates an invoice in accounting or invoicing software that is directly connected to IS EFA. The software then sends the file to the system, where it automatically checks for mandatory requirements, format, and logical errors, such as incorrect ID number, invalid VAT rate, or incomplete customer data. If everything is in order, IS EFA assigns an IDF to the invoice and stores it in the database. Only then can the supplier deliver the document to the customer, either in XML format for machine processing or in visual PDF format supplemented with IDF. Invoices "issued on the knee" without this step will not be valid and risk refusal of performance, sanctions, or the unreality of VAT deduction.
Practical impacts on the daily work of an entrepreneur
The entrepreneur will need software that can handle data export in the state-required format and communication with the Financial Administration system. The invoicing process will be slightly slowed down because an intermediate verification step will be added, but at the same time transparency will increase and later additional sending of invoices to tax authorities will be eliminated. All documents will be archived in a common database, which significantly shortens the duration of checks and eliminates manual searching for old documents.
Benefits of mandatory electronic invoicing
The most significant benefit is a lower error rate. The system will detect formal deficiencies before they are sent to the customer. Tax audits will be faster because the inspector will no longer request physical or e-mailed documents. Data from electronic invoices will offer companies a better overview of receivables and cash flow in real time. In the perspective of several years, the Slovak system is expected to be aligned with European solutions, which will bring simpler cross-border transactions without lengthy data rewriting.
Disadvantages and challenges to consider
The biggest hurdles are the initial investment in new or updated software and the necessary training of employees. The quality of input data will gain even more importance; serial numbers, addresses or VAT rates will have to be correct the first time. Moreover, if the internet connection or the IS EFA itself goes down, invoicing may be interrupted for a certain period of time.
Frequently asked questions and concerns of entrepreneurs
Many people ask whether they will also have to archive XML files locally. The answer is that IS EFA will do the central recording, but the entrepreneur should continue to keep copies in their own system for possible duplication and internal needs. Another common concern is whether it will be possible to correct an incorrect invoice after the IDF has been assigned. In this case, the procedure will be to issue a correction document, which will also go through IS EFA. Finally, the question of costs: small businesses will probably switch to cloud services with a monthly fee, while large companies can invest in individual integrations tied to ERP.