Peppol BIS Billing 3.0 in Latvia: What It Requires

Latvia’s government issued Regulation No. 749 on 9 December 2025, and it spells out exactly what the XML file behind a structured e-invoice sent to the State Revenue Service (Valsts ieņēmumu dienests, or VID) has to look like: the structure follows the UBL 2.1 syntax, and the content must match the Peppol BIS Billing 3.0 specification, known as a CIUS (Core Invoice Usage Specification). Peppol BIS Billing 3.0 is a data format. It defines which fields an invoice must contain and how they’re arranged, not how the invoice has to be routed. It is not a requirement to send the invoice through the Peppol network itself: the same regulation lets trading partners agree instead to use Latvia’s official e-address or plain email. Transmitting e-invoice data to VID is already mandatory for G2G, B2G and G2B transactions since 1 January 2026, the general B2B obligation starts on 1 January 2028, and OpenPeppol’s next BIS Billing 3.0 release becomes mandatory on 17 August 2026, which affects your software’s compatibility, not Latvia’s legal deadline.

What’s the Difference Between Peppol BIS Billing 3.0, EN 16931, UBL 2.1, and a PDF Invoice?

EN 16931 Sets the Content, UBL 2.1 Sets the Syntax

Latvia’s Accounting Law (Grāmatvedības likums) defines a structured e-invoice precisely: it’s an invoice created, sent and received in a structured format that can be processed automatically, and it must comply with the European standard LVS EN 16931-1:2017. That standard is the EU’s shared semantic data model for the core elements of an e-invoice. It says which data (seller, buyer, amounts, VAT) an invoice must carry, but it doesn’t fix what the file itself looks like.

UBL 2.1, or Universal Business Language, is one possible syntax: a technical way of writing that data into an XML file.

Peppol BIS Billing 3.0 Narrows Both Into One Profile

Peppol BIS Billing 3.0 sits one level more specific. It’s a usage profile, a CIUS, that narrows down the combination of EN 16931 and UBL 2.1, fixing which fields are mandatory, what order they come in, and which codes you’re allowed to use. Latvia has already applied this profile to public procurement invoices since 18 April 2019, and the new VID regulation, which took effect on 13 December 2025, extends the same rule to e-invoices sent to VID.

Why a PDF Invoice Doesn’t Qualify

A PDF invoice, however well it’s formatted, is not a structured e-invoice under Latvian law. A machine can’t read a PDF automatically and reliably; only a person can. If your company currently emails PDFs to trading partners, that channel stays permitted for most B2B transactions for a few more years. But the PDF itself doesn’t satisfy the e-invoicing regulation.

Does the Format Requirement Mean Invoices Have to Travel Through the Peppol Network?

This is where most of the confusion starts. OpenPeppol classifies Peppol BIS Billing 3.0 as a specification for invoices and credit notes, not as a description of how the invoice has to physically move.

Channels You Can Use Instead of Peppol

Latvia’s Regulation No. 749 spells out exactly which transmission channels a company may use to send an e-invoice: the official e-address, once the account is activated; a service provider’s channel, run by an operator; or another agreed channel, including direct system-to-system integration or email. Trading partners agree on the channel between themselves, and the law doesn’t force your company to join the Peppol network or run a certified Access Point (Peppol’s network entry point).

The One Case Where Peppol Is Mandatory

The Peppol network becomes the mandatory channel in one narrow case. When a supplier registered or based abroad sends an invoice directly to a central government body, it uses the cross-border Peppol transmission system, which has been written into Latvia’s regulation since March 2022. In every other case, including public procurement, it’s enough that the invoice matches the CIUS and travels over whatever channel the parties agreed on: the e-address, an operator’s interface, or email.

Who Does This Already Apply to in Latvia, and Since When?

Structured e-invoicing in Latvia is arriving in stages. Since 1 January 2025, every Latvian government body and every company registered in Latvia has had to issue structured e-invoices for G2G, B2G and G2B transactions: invoices between state institutions, from companies to the state, and from the state to companies. If your company’s counterpart is a budget institution and the contract was signed on or before 31 December 2024, the e-invoicing requirement applies to that contract no later than 1 January 2026.

In that same segment (G2G, B2G and G2B), transmitting invoice data to VID also became mandatory on 1 January 2026. For B2B (two Latvian-registered companies dealing with each other), data transmission is still voluntary, and stays that way until 31 December 2027. The general B2B obligation, under which a Latvian-registered company issuing a payable invoice to another Latvian-registered company must produce it as a structured e-invoice and hand the data to VID, takes effect on 1 January 2028, not in 2026, as some summaries have gotten wrong.

Latvian law sets no revenue threshold for this: the requirement applies, in principle, to every entity covered by the Accounting Law, including sole traders and anyone subject to VAT rules. The law does carve out specific exceptions: certain cash documents and invoices generated within particular state information systems, for instance, listed in detail further down in the Grāmatvedības likums.

How Does the Invoice Reach Your Partner, and Then VID?

Submission Channels and VID’s Three Data Sources

Your company and your trading partner choose the transmission channel together: the e-address, a service provider’s interface, or another agreed setup. If you use the e-address, submission to VID happens automatically. The e-address information system forwards the message containing the invoice XML to VID on its own, as long as you and your provider are running an up-to-date integration. If you go through an operator connected to VID’s API, the operator handles that technical transmission for you.

VID receives data from three sources: the e-address portal, e-invoice service providers, and taxpayers themselves. Manually, VID’s electronic declaration system (EDS) only accepts an XML file, not a PDF or any other attachment. Accounting software that’s been connected to VID’s e-invoice API can submit the data automatically. VID recommends checking, before you send anything, whether your XML meets the technical and business-logic rules, using the European Commission’s e-invoice validation tool.

Deadlines and Outage Rules

The timing requirement is spelled out in the regulation: the invoice has to be submitted to VID once, within five working days of the day it was sent. If submission fails because of a system outage, you have to report that in VID’s declaration system by the next working day at the latest, and submit the invoice within three working days after the outage is fixed.

What Should Finance and IT Teams Check Before 17 August 2026?

Current Version vs. the Incoming Release

OpenPeppol published the next Peppol BIS Billing 3.0 release on 20 May 2026, and it becomes mandatory on 17 August 2026. The version currently in force was published on 24 November 2025 and took effect on 23 February 2026. Latvian law refers to Peppol BIS Billing 3.0 in general terms, without pinning down a specific version number, so this release doesn’t trigger new Latvian legislation. It does, however, bring new validation rules that invoices will have to pass.

Practical Steps Before the Deadline

In practice, that means the software or provider your company uses to build and send e-invoices has to have rolled out the new validation rules before 17 August 2026. Otherwise invoices can start failing right when validation switches to the stricter specification. Before the deadline, it’s worth asking your accounting software vendor or operator directly which Peppol BIS Billing 3.0 version their system currently runs, and whether a migration is scheduled. It’s also worth running test invoices through the European Commission’s validation tool before the new version takes effect, the same tool VID already recommends using for routine e-invoice checks.