Electronic invoicing
Mandatory in Slovakia from 2027
Electronic invoicing means issuing and delivering invoices as structured, machine-readable files rather than PDFs or paper. Slovakia makes it mandatory for domestic B2B transactions between VAT payers from 1 January 2027; Czechia has no national mandate and follows the EU ViDA timetable instead.
A PDF is not an electronic invoice
This is the most common misunderstanding. An invoice emailed as a PDF is still a document made for a human — software has to extract, guess, and correct the values. A true electronic invoice is a structured file in which every line is a discrete field the system reads without interpretation.
The difference is practical. With a structured invoice there is no retyping into accounting, matching against the order happens automatically, and an amount cannot be wrong because of a typo. It is worth treating less as a tax duty and more as the removal of manual work that costs time every month.
Two different national timetables
In Slovakia, from 1 January 2027 all VAT payers must use a single electronic invoice format based on the European standard — XML in the Peppol BIS profile — for domestic B2B. Delivery runs exclusively through a certified delivery service provider rather than by email, in a five-corner model where the data is also reported to the tax administration. A voluntary phase has been running since the second quarter of 2026, and the duty extends to intra-EU transactions from 1 July 2030.
Czechia has no national B2B mandate today; electronic invoicing is voluntary and needs the recipient's consent. The change will come through the EU ViDA directive: mandatory e-invoicing under EN 16931 for cross-border B2B inside the EU from 1 July 2030, with member states given until January 2035 for domestic transactions and for aligning earlier national schemes.
What to prepare
Most of the work is not in the format but in what data your systems hold. A structured invoice requires line items, VAT rates, partner identifiers, and the order reference to exist as discrete fields rather than as text in a note.
- Partner records in one place, not duplicated across shop, CRM, and accounting.
- Invoice lines tied to the order so matching can be automatic.
- Correct VAT rates, including cross-border sales under OSS.
- An accounting software interface able to hand over and receive an invoice.
- An archive holding structured invoices, not only rendered PDFs.
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Explore custom solutionsFrequently asked questions
When does it become mandatory?
In Slovakia, 1 January 2027 for domestic B2B between VAT payers, with a voluntary phase since the second quarter of 2026 and intra-EU transactions following on 1 July 2030. In Czechia there is no national mandate; EU rules bite for cross-border B2B from 1 July 2030.
Can I just email PDFs?
Not under the Slovak regime. The format must be structured XML to the European standard, and delivery goes through a certified delivery service provider rather than email. A PDF may remain as a human-readable companion at most.
What should I do now?
Check whether your invoicing and accounting systems can issue and receive a structured invoice, and tidy up partner and line-item data. Slovakia's voluntary phase is the chance to test the connection without deadline pressure.