Insights

E-invoicing mandates in Central and Eastern Europe: who must comply, and when

Techtone Group · Oct 12, 2026 · Last reviewed Oct 14, 2026

Mandatory B2B e-invoicing is already live in Poland, Romania and Croatia, Slovakia follows on January 1, 2027, and Bulgaria has proposed January 1, 2028. Hungary and the Czech Republic have no general mandate yet. From July 1, 2030, EU law requires structured e-invoices for cross-border B2B trade everywhere.

The short answer, country by country

Above all of these sits the EU VAT in the Digital Age (ViDA) package, published on March 25, 2025. Since April 14, 2025 member states no longer need EU permission to impose domestic e-invoicing, and from July 1, 2030 structured e-invoices with reporting within ten days become the rule for cross-border B2B supplies inside the EU. Countries that already run their own real-time systems must align them with the EU model by 2035.

Three models, not one

The word "mandate" hides three different designs, and the design decides how much a business has to change.

• Clearance (Poland, Romania, proposed for Bulgaria): an invoice only exists legally once the tax authority platform has accepted it. Billing, ERP and customer communication have to wait for that confirmation, and an outage on the platform becomes a business continuity question.
• Network exchange with reporting (Slovakia, Croatia): invoices travel between companies over a network such as Peppol through accredited providers, and the data reaches the tax authority in parallel. The authority does not approve each invoice.
• Reporting only (Hungary today): the invoice can still be paper or PDF, but its data must reach the tax authority in real time. Companies already comply with the data side, which makes a later e-invoicing step smaller.

Where groups operating across the region get caught out

• One ERP, several national formats. Poland requires its own FA(3) structure through KSeF, Romania uses its CIUS-RO specification, Slovakia and Croatia rely on the European standard EN 16931 over a network. A single regional template rarely works without country adapters.
• Thresholds and grace periods differ. Poland does not apply penalties for invoicing errors until the end of 2026; Bulgaria would start penalties six months after go-live. Planning to the strictest date avoids two migrations.
• Inbound invoices matter as much as outbound. In clearance countries the buyer receives the invoice from the platform, so accounts payable processes, approval workflows and archiving change too.
• Foreign establishments are in scope. Poland covers foreign businesses with a fixed establishment for VAT; Slovakia covers domestic supplies between Slovak taxable persons.

What finance and IT teams should do now

• Map every legal entity and VAT registration in the region against the table above, including fixed establishments.
• Decide per country between building the connection in-house and using an accredited service provider; in Slovakia and Croatia a provider is the normal route.
• Test inbound flows as early as outbound ones, including how invoices enter approval and payment.
• Use the structured data: an invoice that arrives as data can be matched to its payment automatically, which shortens collection and cuts reconciliation work.
• Track Hungary and the Czech Republic: both are expected to move before the 2030 EU date, and Hungary has already consulted on a general mandate.

The payment side is the opportunity

Most projects treat e-invoicing as a compliance cost. The larger prize sits after the invoice: once invoices travel as structured data, payment details, payment links and remittance information can travel with them. Banks, acquirers and invoicing platforms that place a payment option inside the e-invoice can shorten days sales outstanding for their business clients and win payment volume that today moves as manual bank transfers.

This article is general information, not tax or legal advice. Mandates change often; confirm the current rules with the national tax authority before acting.

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