E-invoice from January 1, 2027: what's changing and how to prepare
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February 3, 2026
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The introduction of e-invoices represents one of the most significant legislative changes that will affect invoicing processes in Slovakia in the coming years. The aim of the new system is to introduce a uniform electronic invoice format, reduce the administrative burden on entrepreneurs, and at the same time make data processing by the state more efficient.
The Financial Administration of the Slovak Republic has already started implementing the e-invoice system as part of the changes resulting from the amendment to Act No. 222/2004 Coll. on Value Added Tax (VAT Act). From a practical point of view, this mainly concerns the modernization and digitalization of invoicing processes so that invoices can be processed automatically, in a uniform format and with a minimum of manual intervention. The project is being prepared in cooperation with the professional public, suppliers of accounting and information systems and the business sector, so that the solution can be actually used in practice.
Importantly, the transition to e-invoices will not happen overnight. Voluntary participation is expected to be possible as early as 2026, with widespread use of e-invoices planned from 1 January 2027. Later, the system will be extended to cross-border transactions and will significantly change the way VAT data is reported.
What is an e-invoice and why is it being introduced?
An electronic invoice (e-invoice) is a structured file in XML format, which contains all mandatory invoice data - for example, invoice number, date of issue, subject of delivery, amount, and identification data of both the supplier and the customer.
Unlike a "regular" PDF invoice, XML is designed to be:
easily readable and processable by computers,
suitable for automatic import into systems,
less prone to errors that arise from manual rewriting.
The purpose of the change is to process billing data automatically, which will reduce errors and administration, while also providing the state with a more accurate and faster overview of transactions.
How will the e-invoice be delivered?
Electronic invoices will be sent and received exclusively via certified delivery service provider, often referred to as the "Digital Postman." It will ensure the distribution of invoices between sender and recipient in a uniform electronic format.
Entrepreneurs will be able to use the following services:
through accounting/economic software,
via the web interface,
or via the mobile app.
It is important that the entrepreneur must be able to invoice to give and receive, because accepting electronic invoices will be part of the legal obligation.
The financial administration is supposed to publish and continuously update the list of certified providers. According to your documents, the following applies: As of the date of writing the article, the financial administration had not yet registered the contracted Digital Postman..
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E-invoice implementation schedule
1) Voluntary testing from 2026
Entrepreneurs will be able to voluntarily start testing the e-invoice delivery system. The first step will be to select a Digital Postman and connect to it (either via software or via a web/mobile application).
2) Mandatory domestic e-invoices from 1. 1. 2027
In the period from 1 January 2027 to 30 June 2030 VAT payers are required to:
issue and receive invoices in a specified electronic format,
electronically report selected data from domestic deliveries of goods and services.
The obligation to issue e-invoices should apply to for domestic transactions.
3) Changes from 1 July 2030: cross-border + end of KV/SV
From July 1, 2030 The system will be extended to cover cross-border transactions (EU and third countries). At the same time, digital data reporting is being introduced on a wider scale, and the result should be:
cancellation of VAT control report,
cancellation of summary report,
because the data will be reported to the tax administrator electronically through the new system.
Who will be subject to the obligation?
The introduction of e-invoices should concern exclusively business entities. At the same time, however, there is an important practical impact: e-invoices will be mandatory for all taxable persons to whom the VAT payer is obliged to issue an invoice under the VAT Act.
In practice, this means that the obligation to accept e-invoices will not only apply to traditional companies and self-employed persons, but also to persons such as:
lawyers, notaries, artists,
self-employed farmers,
architects,
persons renting real estate.
Your background also reveals a fundamental thing: even if a specific subject is not a VAT payer, may be mandatory be able to accept e-invoices, if the supplier is required by law to send it to him.
How invoicing can work in practice
If the accounting software is connected to the Digital Postman
Typical procedure:
an entrepreneur or accountant issues an invoice in the software,
the invoice is sent to the Digital Postman directly from the system,
The digital postman will deliver it to the subscriber,
the customer confirms receipt/access.
If an entrepreneur uses the Digital Postman web/mobile application
the entrepreneur logs into the application,
issues the invoice in its system and saves it as a file,
in the application it is loaded and sent,
He can then look for a delivery receipt.
Practical tip from the documents: it is wise to check whether the application will be able to display the e-invoice as well in PDF, so that it can also be recorded manually if the software does not support fully automatic import.
Reporting data to the financial administration and fines
The system includes an obligation to report selected data from issued and received invoices to the financial administration. The Digital Postman is supposed to extract and report the data automatically:
on the supplier's side at the time of execution, no later than 15 days,
on the customer's side upon receipt, no later than 5 days from the receipt of the e-invoice by the Digital Postman.
However, the responsibility for reporting remains with the entrepreneur (both supplier and customer). Violation of obligations may result in a fine:
to 10 000 €,
in case of repeated violation up to 100 000 €.
However, according to the documents, a fine should not be imposed if:
This is an obvious mistake and the error is immediately corrected,
the entrepreneur proves the failure of the Digital Postman and the data was reported immediately after the fault was eliminated.
Sending an e-invoice without the consent of the customer and Peppol ID
A significant change from practice: if an entrepreneur sends an invoice via Digital Postman and it is in the correct format, does not require the recipient's consent. This also applies during the voluntary phase in 2026.
The condition is that the customer has a valid Peppol ID (practically an "address" for invoice delivery).
Exceptions: when e-invoice will not be possible
There are also cases where electronic invoices may not be issued. This applies in particular to:
classified transactions,
supplies for state security forces (e.g. Slovak Information Service, Military Intelligence).
In such situations, classic paper invoices or other existing forms should be used.
How to prepare in 2026
From a companies' perspective, 2026 will be a crucial year for setting up processes and minimizing risks. In practice, we recommend:
monitor the list of certified Digital Postmen and choose a solution in time,
check the readiness of the accounting software and the integration plan,
set up an internal process for receiving e-invoices (not just issuing them),
agree with the accountant on the method of processing and archiving (including PDF form for review),
take into account possible costs: for smaller companies, a simple subscription is expected to range between €5 to €12 per month.