Reporting e-invoice data to the Financial Administration (SK TDD)

In short

• Data from an e-invoice that a VAT payer must issue and sends through the delivery service are reported to the Financial Administration.
• The report is made through the digital postman and the duty is fulfilled by handing the e-invoice to the delivery service.
• The report (Tax Data Document, TDD) is created and sent by the postman, not by the accountant.
• The government bill (print 1454), in first reading on 30 September 2026, proposes abolishing the customer’s duty to report data from received e-invoices.

Why there is a report at all

The point of the reform is not only a digital invoice between businesses but also continuous reporting of data to the tax administrator (so-called e-reporting). Invoice data will be sent to the Financial Administration automatically, in near real time (FS FAQ, part I, question 9).

The aim is for selected invoice data to reach the Financial Administration in structured form, which allows more efficient analysis, cross-checking and better detection of risky or fraudulent VAT transactions. This does not give the Financial Administration access to all your documents: the scope of the reported data and the purpose of their processing are set by the VAT act (FS guide for non-governmental organisations).

Who reports and when

Under § 85o of the VAT act as amended by Act No. 385/2025 Coll., from 1 January 2027:

• A supplier that is a VAT payer reports the data from an e-invoice it is obliged to issue and sends through the delivery service at the time of its issue (§ 85o(9)). The five-day deadline applies only to self-billing, where the customer issues the invoice on behalf of the supplier (FS FAQ, part II, question 53).
• A customer that is a VAT payer is, under the wording in force, to report the data from an e-invoice received through the delivery service within five days of receipt (§ 85o(10), FS FAQ, part I, question 18).
• Data are reported through the delivery service and the duty is considered fulfilled by handing the e-invoice to the delivery service (§ 85o(11), quoted in FS FAQ, part II, question 20).

Note on the government bill: the government bill (print 1454), status on 30 September 2026 in first reading in the National Council of the Slovak Republic, proposes deleting § 85o(10), that is, the customer’s duty to report data from received e-invoices, together with the associated penalties. According to the explanatory memorandum, the data reported by the supplier’s postman are “de facto” the same as those the customer’s postman would report. Until parliament passes the bill, the current wording applies.

Tax Data Document (TDD)

The carrier of these data is the Tax Data Document (TDD): a separate structured document derived from the invoice. It is not a copy of the invoice: it contains the fields the law requires to be reported (the tax identification numbers of the supplier and the customer and selected invoice particulars under § 74(1) of the VAT act, § 85o(9)).

Corrective invoices

Data are reported also from a document that amends the original e-invoice (for example a credit note). If the original e-invoice was sent through the delivery service, the document amending it must meet the same conditions and be sent through the delivery service too (§ 85o(5)). Under the wording in force, the sequential number of the original e-invoice and the data that change are reported from it (§ 85o(9)(c)). The government bill (print 1454), status on 30 September 2026 in first reading, proposes that all data specified by law be reported from the corrective invoice together with the sequential number of the original invoice, not only the changed data.

Voluntary participation in 2026

If you join the network voluntarily already in 2026, the sender’s postman will send the data to C5 already this year, once both C2 and C5 are ready for it; invoices on which the issuer has a VAT ID are reported. The same regime applies in 2027 (FS FAQ, part I, question 44).

The five-corner model in practice

To the usual four corners of the Peppol network (the sender, its access point, the recipient’s access point, the recipient) the Slovak solution adds:

• C5: the endpoint of the Financial Administration that receives the TDD (FS FAQ, part II, question 51).
• C6: the Financial Administration itself, which processes the data.

The endpoint of the Financial Administration is addressed in the network with scheme 0242. The sender’s postman (C2) and the recipient’s postman (C3) thus send the respective TDD to C5 alongside the invoice. Companies do not have to do anything.

Who creates the TDD

Responsibility for the technical creation of the TDD lies with the provider of the delivery service that the entity has under contract (FS FAQ, part II, question 20). Depending on whether you are the supplier or the customer in the transaction, the report arises on the respective side:

• When an invoice is sent (you are the supplier), the sender’s postman creates and sends the TDD.
• When an invoice is received (you are the customer), the recipient’s postman creates and sends the TDD.

What matters is that the TDD is correctly assigned to the taxpayer and to the original invoice; otherwise the data would be matched incorrectly. That is why the quality of the TDD generator matters.

What it means for your company

With a good provider you do nothing extra: you receive or send an invoice and the data report runs automatically in the background. When choosing a provider, check in particular:

• whether it generates and sends the TDD both when an invoice is sent and when it is received,
• whether it shows, next to the document, when the report was sent and when the Financial Administration accepted it,
• what it does if the Financial Administration’s endpoint is temporarily unavailable, and whether it alerts you.

Further questions to ask a provider are summarised in the selection checklist. Errors in reporting are penalised; an overview of the penalties and of the proposed tolerance period is in the article on e-invoicing penalties.

How we do it

Verteco operates its own access point and we generate and send the report automatically: the endpoint of the Financial Administration (C5) has been accepting reports since September 2026. Next to the document in the portal you see when we handed the report to the Financial Administration, and in the API the document also carries the C5 response (field fsReport). TDD generation was part of our OpenPeppol conformance certification. The report is part of the service at no extra charge: receiving without the archive is free up to 1,000 invoices a month (sent and received together), the service with sending or the Data archive costs €2 excluding VAT per IČO (company registration number) per month; nothing is billed before 1 January 2027.

Note

The exact technical parameters (TDD version, binding identifiers, dates) are published and updated by the Financial Administration of the Slovak Republic, including the Slovak document “Najčastejšie otázky a odpovede k eFaktúre” (9/DPH/2025/IM, version of 15 September 2026). This article is for information only and does not replace legal or tax advice.

Frequently asked questions