PEPPOL E-invoicing in Bulgaria 2026 — The Complete Handbook

2026-04-27

PEPPOL Bulgaria 2026: what it is, B2G obligations, 4-corner model, registration, EU Directive 2014/55. Expert handbook by Fakturka.bg.

PEPPOL E-invoicing in Bulgaria 2026 — The Complete Handbook

Electronic invoicing in Europe has entered a new era. PEPPOL — Pan-European Public Procurement OnLine — is establishing itself as the common European standard for exchanging structured electronic documents between businesses and public authorities. For Bulgarian companies that work with European clients or take part in public procurement, PEPPOL is no longer a "technology experiment" — it is a concrete business requirement of growing weight. In this in-depth handbook we cover everything: history, architecture, standards, registration, obligations, benefits and the road ahead.

TL;DR (quick read):

• PEPPOL is a European network for exchanging structured electronic invoices (UBL 2.1 / BIS Billing 3.0).
• B2G (Business-to-Government) e-invoicing has been mandatory across the EU since 2019 — public authorities must accept e-invoices under EU Directive 2014/55/EU.
• B2B in Bulgaria is voluntary in 2026 — but Poland, Germany and Italy are rolling out staged mandates.
• The architecture is the 4-corner model — sender → Access Point → Access Point → recipient.
• Fakturka.bg supports PEPPOL as a one-click toggle in its Pro and Business plans.

Table of contents

1. What PEPPOL is
2. History and evolution
3. The 4-corner model — how it works
4. PEPPOL Network, Access Point and SML
5. Standards — UBL 2.1 and BIS Billing 3.0
6. EU Directive 2014/55/EU
7. When it is mandatory in Bulgaria
8. Other EU variants — EHF, OIOUBL, FatturaPA
9. Registering on the PEPPOL Network
10. Mandatory fields of a PEPPOL invoice
11. PDF invoice vs PEPPOL e-invoice
12. Benefits for business
13. Benefits for governments
14. Roadmap for Bulgaria
15. Other EU countries (Poland, Germany, Italy)
16. How Fakturka.bg supports PEPPOL
17. Technical challenges
18. Common mistakes
19. Frequently asked questions (FAQ)
20. Related articles and sources

1. What PEPPOL is

PEPPOL (Pan-European Public Procurement OnLine) is a set of technical specifications, business rules and a legal framework for exchanging structured electronic business documents between organisations in Europe and beyond. It is governed by OpenPeppol AISBL — a non-profit association based in Brussels.

PEPPOL is not software — it is a standard. The concrete software solutions that send and receive PEPPOL documents are called Access Points (AP). Each AP is certified by OpenPeppol and follows common interoperability rules.

The documents that travel through PEPPOL are not just PDFs — they are machine-readable XML files in UBL 2.1, enriched with PEPPOL BIS Billing 3.0 rules. This enables automatic processing by the recipient's ERP / accounting system without manual entry.

2. History and evolution

• 2008: PEPPOL launches as an EU initiative to standardise e-invoicing in public procurement.
• 2012: Pilot phase ends. Standards are approved.
• 2014: EU Directive 2014/55/EU is adopted — requiring all public authorities in the EU to accept e-invoices by 2019.
• 2019: Mandatory B2G processing takes effect across all member states.
• 2020-2024: Expansion outside the EU — Australia, Singapore, Japan and New Zealand join.
• 2025-2027: Staged B2B mandates in Poland (KSeF), Germany, Belgium.
• 2026: The EU's ViDA package (VAT in the Digital Age) plans mandatory B2B e-invoicing on cross-border supplies from 2030.

3. The 4-corner model — how it works

PEPPOL uses the so-called 4-corner model for exchanging documents:

[Corner 1]              [Corner 2]              [Corner 3]              [Corner 4]
Sender        →   Access Point     →   Access Point     →   Recipient
(SME / ERP)         (sender's AP)         (recipient's AP)        (ERP / accounting)

Steps:

1. Corner 1 (sender) generates a UBL 2.1 invoice from ERP / Fakturka and hands it to its Access Point.
2. Corner 2 (sender's AP) validates the document against PEPPOL BIS rules, signs it and looks up the recipient's AP through the Service Metadata Locator (SML).
3. Corner 3 (recipient's AP) accepts the document, validates it and passes it to the recipient's accounting/ERP system.
4. Corner 4 (recipient) processes it automatically — without manual entry.

Key insight: sender and recipient do not communicate directly. They only know their own Access Points. This makes the network highly scalable — every new participant connects to one AP and automatically reaches every other participant on the network.

4. PEPPOL Network, Access Point and SML

PEPPOL Network

The global network of connected Access Points, each identified by a unique PEPPOL Participant Identifier (e.g. 0007:1234567890 for a Swedish company, 9930:DE123456789 for a German one).

Access Point (AP)

Software or service certified by OpenPeppol. Responsible for:

• Accepting documents from connected clients.
• Validating against PEPPOL BIS rules.
• Routing to the recipient's AP.
• Delivery and acknowledgement.

Bulgaria has several certified APs (see the list at peppol.org).

Service Metadata Locator (SML)

A global DNS-like registry that maps PEPPOL Participant Identifiers to their AP's address. Centrally managed by OpenPeppol.

Service Metadata Publisher (SMP)

A database on each AP that describes which document types each participant can receive (BIS Billing 3.0, Order, Despatch Advice, etc.).

5. Standards — UBL 2.1 and BIS Billing 3.0

UBL 2.1 (Universal Business Language) is an XML standard for business documents — invoices, orders, confirmations, notes. Managed by OASIS.

BIS Billing 3.0 (Business Interoperability Specifications) is the PEPPOL "profile" over UBL 2.1 that defines:

• Which UBL fields are mandatory.
• Business rules for consistency (e.g. total = sum of lines + VAT).
• Code tables (currencies, units of measure, VAT categories).
• Schematron validation rules.

The result is a strictly standardised XML document that guarantees automated processing by any receiving ERP without manual intervention.

6. EU Directive 2014/55/EU

EU Directive 2014/55/EU requires all public authorities in the EU to accept structured electronic invoices in public procurement. Implemented in Bulgaria through amendments to the Public Procurement Act and subordinate regulations.

Scope:

• State and municipal administrations.
• Hospitals, universities, state-owned enterprises.
• Any entity covered by the Public Procurement Act.

Obligation:

• Public authorities must be able to accept e-invoices.
• Suppliers may (and in some countries must) send e-invoices.

In Bulgaria today this is an option, not an obligation, for suppliers. A mandatory B2G mandate is expected within the next 2-3 years.

7. When it is mandatory in Bulgaria

As of 2026:

• B2G: public authorities must accept e-invoices. Suppliers have the option, but not the obligation, to send a PEPPOL invoice.
• B2B: entirely voluntary. There is no mandate for the private sector.
• B2C: not applicable — PEPPOL is for business transactions.

Forecast 2027-2030:

• Staged B2G mandate for state suppliers.
• EU's ViDA — mandatory B2B e-invoicing for cross-border supplies from 2030.
• Possible national B2B mandate following Poland / Germany.

8. Other EU variants — EHF, OIOUBL, FatturaPA

Before PEPPOL became the common standard, each country developed its own:

• EHF (Norway) — Elektronisk handelsformat. Now PEPPOL-compatible.
• OIOUBL (Denmark) — Offentlig Information Online UBL. Local variant, partly PEPPOL-compatible.
• FatturaPA (Italy) — mandatory national format for B2B and B2G since 2019. Not PEPPOL, but converters exist.
• KSeF (Poland) — Krajowy System e-Faktur. Mandatory B2B from 2026 with a national format.
• XRechnung (Germany) — national CIUS over EN 16931, PEPPOL-compatible.

The trend is convergence with PEPPOL through CIUS (Core Invoice Usage Specification) over EN 16931.

9. Registering on the PEPPOL Network

Registration is not direct with OpenPeppol — it goes through an Access Point provider. The procedure:

1. Choose an AP: compare price, support, integrations (Fakturka.bg, ERP software). List: peppol.org/who-is-who.
2. Contract: sign an SLA with the AP.
3. Participant Identifier registration: the AP registers your company with the PEPPOL SML and SMP.
4. Onboarding: test invoice → confirmation → production access.
5. Timeline: typically 1-2 weeks.

Cost: varies — from ~50 BGN (25.57 EUR) per month for SME plans to corporate solutions with per-document pricing.

10. Mandatory fields of a PEPPOL invoice

A PEPPOL BIS Billing 3.0 invoice must contain:

• Invoice number and date.
• Document type (380 = standard invoice, 381 = credit note).
• VAT identification numbers of supplier and recipient.
• Addresses and country codes (ISO 3166).
• Currency (ISO 4217).
• Lines with quantity, unit of measure (UN/ECE Rec. 20), price, description.
• VAT category (S = standard, Z = zero, E = exempt, AE = reverse charge).
• Total taxable amount, VAT, amount due.
• Payment terms, IBAN, BIC.
• PEPPOL Participant Identifier.

The XML file is typically 5-15 KB.

11. PDF invoice vs PEPPOL e-invoice

12. Benefits for business

• Automation: the recipient drops the invoice straight into accounting without manual entry.
• Faster payment: average DSO (Days Sales Outstanding) drops by 7-15 days.
• Fewer errors: standardised fields and validation eliminate ~95% of common mistakes.
• Audit trail: every step of the 4-corner model is logged and signed.
• Digital integration: easy hookup with ERP, accounting, banking.
• Regulatory readiness: zero-migration when mandates kick in.

13. Benefits for governments

• Real-time VAT data: reduces VAT fraud.
• Procurement transparency: every invoice is digitally traceable.
• Lower admin cost: ~80% less paper invoice handling.
• Faster audits: structured data is analysed algorithmically.
• Fraud detection: AI flags suspicious patterns.

14. Roadmap for Bulgaria

2026: PEPPOL available voluntarily through certified APs. Public authorities accept e-invoices under EU Directive 2014/55.

2027-2028: Expected mandatory B2G — suppliers to the state send only e-invoices.

2029-2030: EU's ViDA package — mandatory B2B e-invoicing for cross-border supplies.

2030+: Possible national B2B mandate (watching Poland / Germany).

Fakturka.bg has integrated PEPPOL with a one-click toggle for sending through the PEPPOL Network on Pro and Business plans.

15. Other EU countries (Poland, Germany, Italy)

Poland — KSeF

The mandatory national B2B e-invoicing system KSeF rolls out in stages from 2026. All Polish invoices must pass through a centralised state portal.

Germany — staged 2025-2027

• 2025: Every business must be able to receive e-invoices.
• 2027: Mandatory sending of e-invoices for B2B transactions (with phased roll-in for SMEs).

Italy — FatturaPA

Italy is the B2B e-invoicing leader — mandatory since 2019. All invoices pass through the state's Sistema di Interscambio (SdI).

Belgium — 2026

Mandatory B2B e-invoicing from January 2026 over the PEPPOL network.

16. How Fakturka.bg supports PEPPOL

Fakturka.bg ships PEPPOL support with:

• One-click toggle: "Send via PEPPOL" alongside "Send by email" and "PDF download".
• Automatic UBL 2.1 generation: the system converts the internal invoice model into BIS Billing 3.0.
• Certified AP partnership: through a contract with a European Access Point provider.
• Automatic SML lookup: finds the recipient's AP by UIC / VAT number.
• Inbound support: receive PEPPOL invoices straight in the Fakturka.bg dashboard.
• Pricing: included in Pro and Business plans, no per-document fees.

17. Technical challenges

• ERP integration: older ERP systems lack UBL 2.1 export — middleware is needed.
• Master data quality: PEPPOL requires accurate VAT numbers, IBANs and country codes — many companies have stale or inaccurate data.
• Validation rules: BIS Schematron rules are strict — every error stops the invoice.
• Multi-tenant scenarios: holding structures with several legal entities require careful SMP setup.
• Standard versioning: UBL and BIS evolve — APs must support multiple versions.

18. Common mistakes

• Wrong Participant Identifier format — e.g. using a UIC without the correct schema prefix.
• Invalid recipient VAT number — not validated in VIES.
• VAT rounding: a 0.01 BGN gap between line and total → rejection.
• Missing mandatory VAT category (S, Z, E, AE).
• Wrong country code — using "BUL" instead of "BG".
• Missing BIC/SWIFT alongside IBAN.
• Date in wrong format — PEPPOL requires YYYY-MM-DD (ISO 8601).

Frequently asked questions (FAQ)

What is PEPPOL?

PEPPOL (Pan-European Public Procurement OnLine) is a European standard and network for exchanging structured electronic business documents — primarily invoices — between companies and public authorities.

When is it mandatory in Bulgaria?

As of 2026: voluntary for B2B; necessary for B2G, since public authorities must accept e-invoices under EU Directive 2014/55. A staged obligation for state suppliers is expected in 2027-2028.

What is the difference between PEPPOL and a regular email PDF invoice?

A PDF is a visual document — it requires manual entry. A PEPPOL invoice is a structured UBL 2.1 XML document, processed automatically by the recipient's ERP through the 4-corner network.

How much does PEPPOL integration cost?

Prices range from ~50 BGN (25.57 EUR) per month for SME packages to corporate solutions with per-document pricing. Through Fakturka.bg, PEPPOL is included in Pro / Business plans with no extra fees.

Can a small business use PEPPOL?

Yes — through invoicing platforms like Fakturka.bg that provide PEPPOL as an add-on. You don't need your own Access Point.

What is an Access Point?

A software service certified by OpenPeppol that accepts, validates and delivers PEPPOL documents. Each network participant has its own AP — sender and recipient only need to know their own.

Is the format XML or PDF?

PEPPOL is XML in UBL 2.1 with the PEPPOL BIS Billing 3.0 profile. A PDF can be attached as an annex but does not replace the structured XML.

Which EU countries are leading?

Italy (mandatory since 2019), Poland (KSeF from 2026), Germany (staged 2025-2027), Belgium (2026), the Nordics (Norway, Denmark, Sweden — for years already).

How does Fakturka.bg send PEPPOL invoices?

Through a certified European Access Point partnership. From the dashboard: open the invoice → "Send via PEPPOL" → automatic UBL 2.1 generation → routing through the recipient's AP.

What are the penalties for non-compliance (B2G)?

Currently no direct penalties for the sender in Bulgaria — there is no supplier mandate. Penalties exist for public authorities that fail to accept e-invoices under EU Directive 2014/55. After the upcoming B2G mandate, supplier penalties will be defined.

Related articles

• Complete Guide to Invoicing in Bulgaria 2026
• EU E-invoicing Mandates Timeline 2026-2030

Sources

• ZDDS Art. 114 (lex.bg) — invoice fields
• peppol.org — official OpenPeppol portal
• EU Directive 2014/55/EU — mandatory B2G e-invoicing
• EU Digital Building Blocks — technical specification
• UBL 2.1 (OASIS) — XML document standard
• PEPPOL BIS Billing 3.0 — specification and validation rules
• VIES — VAT Information Exchange System

Last updated: 2026-04-27 Author: The Fakturka.bg team