Romania’s RO e-Factura B2B e-invoicing mandate, explained

Since 1 January 2024, Romania requires structured electronic invoices for domestic B2B transactions between taxpayers established in Romania. A PDF attached to an email is not enough: the invoice has to be a machine-readable XML document conforming to RO_CIUS — Romania’s national rules layered on the European standard EN 16931 — and submitted to the government’s RO e-Factura platform, operated by the tax authority ANAF, within five calendar days of issuance. Unlike Belgium’s Peppol-first route, Romania uses a central-clearance model: every invoice passes through a government system.

This page explains what the mandate is; it is not legal or tax advice. Scope, exemptions, deadlines, and penalties are set by Romanian law (Law 296/2023, Order 1366/2021) and ANAF, and the details can change. Confirm your own obligations — and your route into the RO e-Factura system — with ANAF or a qualified adviser before you rely on a specific rule or date. Slipstack tracks the invoice format, not your filing or submission status.

What the mandate requires

For in-scope B2B transactions, the supplier must issue a structured electronic invoice and transmit it to the RO e-Factura platform within five calendar days of issuance. “Structured” means the invoice data lives in a defined XML model — not pixels in a PDF and not a flat image. In practice that means an invoice built to the EN 16931 core data model and Romania’s RO_CIUS national restriction, carried in the UBL 2.1 (or CII) syntax. Once submitted, ANAF validates the file and applies its electronic seal; only the sealed invoice in the system is the legally valid one. Late or non-compliant submission is subject to fines scaled by taxpayer size.

Who is in scope

The B2B mandate targets taxpayers established in Romania invoicing each other domestically; B2G has required EN 16931 invoices since 2020, and high-risk sectors (such as construction and alcohol) were pulled in earlier, from July 2022. A separate B2C phase began voluntarily on 1 July 2024 and became mandatory on 1 January 2025, also reported within five calendar days. Because the boundaries — non-established suppliers, exempt flows, and edge cases — are defined in law and updated by ANAF, treat the summary above as orientation, not a determination: check your specific situation with the authority or your accountant.

The format: RO_CIUS on top of EN 16931

Romania’s format is RO_CIUS (defined by Minister of Finance Order 1366/2021). RO_CIUS is a CIUS — a Core Invoice Usage Specification — layered on top of EN 16931: it takes the European core invoice model and adds its own mandatory fields and code-list constraints, and it uses the UBL 2.1 syntax (CII is also part of EN 16931). So a RO_CIUS invoice is always EN 16931 core compliant, but the reverse is not automatic — RO_CIUS asks for more than the core alone. See what EN 16931 is for the core model and the UBL vs CII distinction.

How RO e-Factura works (central clearance)

RO e-Factura is a government-run clearance platform, not a peer-to-peer network. The supplier uploads the invoice XML to the platform through ANAF’s SPV (Spațiul Privat Virtual / Virtual Private Space) or an integrated API; ANAF validates it, applies a digital seal, and makes the sealed invoice available to the buyer. This continuous transaction control (CTC) model — the tax authority sits in the middle of every invoice — is closer to a mandated routing platform than to Peppol’s four-corner network. Producing a correct invoice file and getting it into RO e-Factura are two separate jobs.

Where Slipstack fits — and where it does not

Slipstack is on the document side of that split, not the platform side. From one JSON call it can:

Generate an EN 16931 core invoice in UBL or CII syntax, or a Factur-X / ZUGFeRD PDF with the XML embedded.
Validate the EN 16931 core business rules for free before you send anything, with the EN 16931 / XRechnung core validator.

What Slipstack does not do: it is not connected to ANAF or the SPV, it does not submit invoices to RO e-Factura, and it does not register you with the platform. It also covers the EN 16931 core, not the additional RO_CIUS national rules — so a core-valid invoice from Slipstack is a correct starting point, but your accounting software, integrator, or ANAF submission flow is responsible for full RO_CIUS conformance and clearance. For what a mandated routing platform is, see what is a PDP.

Generate EN 16931 core invoices from one JSON call

Emit compliant UBL / CII XML or a Factur-X PDF, and validate the core rules for free first. Bring your own RO e-Factura submission route for clearance.

See pricing Validate an invoice free