Decoding Slovakia’s E-Invoicing Mandate: Expert Q&A
Slovakia is set to become the first country in Europe to implement a full 5‑corner e‑invoicing architecture, a model that is widely seen as an early blueprint for the EU’s upcoming VAT in the Digital Age (ViDA) initiative. For businesses operating in Slovakia, this means adapting corporate systems to real‑time reporting, decentralized invoice transmission, and a new set of technical identifiers, well before the mandate becomes binding.
We hosted a dedicated webinar, “Decoding Slovakia’s E‑Invoicing: How the 5‑Corner Architecture Impacts Your Corporate Systems Before ViDA,” featuring Rafał Trojanowski, Analyst & E‑Invoicing Expert at Comarch, and Ján Skorka, Director of Indirect Tax at PwC Bratislava. Below, you will find answers to some of the most pressing questions raised during the session.
Mandate Scope, Document Types & Timelines
1. In Poland, we are obliged to include a UUID in VAT reports. Is it possible that we will face the same situation in Slovakia?
You will not face the exact same manual reporting requirements in Slovakia as in Poland. In Poland, taxpayers must explicitly include the unique KSeF invoice identifier within their VAT ledger (JPK_V7). In Slovakia, while the e-invoicing architecture utilizes two types of UUIDs, Version 4 (a random, technical ID used to track transmission instances) and Version 5 (a deterministic, hash-based ID calculated from five mandatory invoice fields), these are calculated and embedded within the Tax Data Document (TDD) on the Access Point level.
2. When will authorities officially communicate affected document types? Is there any deadline provided?
Slovakia utilizes formats compliant with the European EN 16931 standard. Within the Peppol network, the allowed billing document types are split between standard billing and self-billing profiles. You can review the full list of supported document types on Peppol’s official documentation page.
3. How will the e-reporting rules affect today’s VAT return submission? Will we need to manually reconcile our electronic VAT ledger records with the figures on today’s return before filing?
The rollout of real-time e-reporting will not immediately replace your standard tax filings. Slovak transitional rules specify that KV DPH obligations continue to apply to all tax periods ending on or before June 30, 2030. The technical generation and submission of TDDs is handled in the background by your provider.
4. Is the e-invoicing process relevant for all types of tax documents, including tax invoices for advance payments or pro forma invoices?
The scope is strictly limited to documents that meet the legal definition of an invoice under Section 72 of the Slovak VAT Act. Invoices for advance payments are therefore in scope, whereas pro forma invoices are out of scope.
5. Are you fully confident that the purchaser's obligation to e-report received invoices will be removed? You mentioned it hasn't been approved by Parliament yet.
The general expectation is that this draft legislation will be successfully passed into law, formalizing the grace period and the delayed reporting obligations. The exact progress of the legislation can be tracked directly on the Slovak e‑legislation portal.
6. What's the deadline to register your AP provider?
The absolute legal deadline to have a registered Access Point provider configured and running is January 1, 2027, when domestic B2B and B2G e-invoicing becomes mandatory. However, it is strongly recommended to start the configuration sooner.
7. Does the mandate create any obligations for non‑Slovak entities with a Slovak VAT registration?
No. Non-Slovak (foreign) entities that are only registered for Slovak VAT under § 5 of the VAT Act have absolutely no e-invoicing or e-reporting obligations during Phase 1, which runs from January 1, 2027, to June 30, 2030.
The 5‑Corner Model: Technical Requirements & Practical Implementation
8. Should buyer‑level rejections be handled through Peppol BLR flow (C4 to C3 to C2 to C1), or can they be communicated through traditional means, such as sending the rejection reasons through email?
The Slovak Financial Directorate has explicitly stated that there is no legal obligation or standardized technical mechanism under Slovak law to send business-level rejections through Peppol.
9. Is it possible to download purchase invoices directly from the Financial Directorate?
No, it is not possible to download purchase invoices directly from the Financial Directorate. Under the Slovak 5-corner architecture, electronic invoices are distributed in a decentralized manner, flowing directly from the supplier’s Access Point to the customer’s Access Point via the Peppol e-delivery network.
10. Is the authorization token generated instantly?
Yes, the authorization token is generated instantly through a fully automated process on the Slovak national onboarding portal.
11. Does the buyer (C4) need to acknowledge receipt before the Message Level Status (MLS) can be sent back to the supplier’s side (C3 to C2)?
The buyer (C4) does not need to manually review, accept, or process the invoice in their ERP system for the MLS to be generated. The MLS is a purely technical validation document.
12. Do we need to do any preparation work, such as checking that our vendor and customer master data (ICO, VAT numbers, and so on) is correct, or will this be checked by the system during implementation?
In general, the taxpayer's system needs to be able to populate all required fields. A detailed description can be found here.
Have more questions about Slovakia’s e‑invoicing mandate or the 5‑corner architecture?
