Bulgaria E-Invoice Format: PEPPOL BIS & XML Requirements Explained

Learn the technical requirements for Bulgaria's NRA e-invoicing mandate starting April 2026. Explore PEPPOL BIS 3.0 standards and compliance rules. This guide gives the answer first, then explains mandate scope, required invoice data, technical format, penalties, official authority context, and practical compliance steps for businesses preparing or reviewing their local e-invoicing workflow.

Overview of Bulgaria’s E-Invoicing Landscape

Bulgaria is transitioning to a mandatory e-invoicing framework governed by the National Revenue Agency (Национална агенция за приходите - NRA).

Bulgaria is transitioning to a mandatory e-invoicing framework governed by the National Revenue Agency (Национална агенция за приходите - NRA). The primary mandate for Business-to-Government (B2G) transactions is set for April 2026, while Business-to-Business (B2B) mandates are expected to follow in 2027. All VAT-registered businesses—those exceeding the BGN 100,000 (~€51,000) annual turnover threshold—must comply with the XML-based PEPPOL BIS 3.0 format. Failure to adhere to these standards can result in significant penalties ranging from BGN 500 up to BGN 10,000 per invoice for systematic non-compliance.

What is the NRA E-Invoice System?

The NRA E-Invoice System is the centralized platform designed to monitor and validate financial transactions across Bulgaria.

The NRA E-Invoice System is the centralized platform designed to monitor and validate financial transactions across Bulgaria. By leveraging the European standard for electronic invoicing (EN 16931), Bulgaria aims to reduce the VAT gap and streamline cross-border trade within the EU. The system relies on the transmission of structured XML data, effectively phasing out paper-based invoices and unstructured PDFs for VAT-registered entities.

For businesses seeking to stay ahead of these regulatory changes, integrating robust invoicing software that supports the PEPPOL network is essential. This ensures that every document issued meets the technical specifications required by the National Revenue Agency.

The Technical Standard: PEPPOL BIS 3.0 and XML Requirements

Bulgaria has adopted the PEPPOL BIS Billing 3. 0 specification as its core format.

Bulgaria has adopted the PEPPOL BIS Billing 3.0 specification as its core format. This is an implementation of the European Standard EN 16931. The format uses Universal Business Language (UBL) 2.1 to define the structure of the XML document. Under this standard, every invoice must contain specific data components to be legally valid.

Key Data Fields in Bulgarian E-Invoices

• Invoice Number: A unique, sequential identifier.
• Issue Date: The date the invoice was generated.
• Supplier/Buyer Information: Names, addresses, and VAT numbers (DDS numbers).
• VAT Rates: Standard rate of 20% or the reduced rate of 9% for specific services like tourism.
• Line Items: Description of goods/services, quantities, and unit prices.
• Total Amounts: Net amount, VAT amount, and total gross amount.
• Currency: Primarily BGN (Lev), though EUR is common for international trade.

Implementing these fields correctly requires advanced compliance features that automatically map local accounting data to the PEPPOL XML schema. Manual entry of these XML tags is prone to error and highly discouraged by the NRA.

Mandate Timeline and Thresholds

The rollout of e-invoicing in Bulgaria is phased to allow businesses time to adapt their internal accounting tools.

The rollout of e-invoicing in Bulgaria is phased to allow businesses time to adapt their internal accounting tools. The current roadmap presented by the Ministry of Finance and the NRA includes the following milestones:

Businesses falling under the VAT registration threshold of BGN 100,000 are currently exempt from mandatory B2B reporting but are encouraged to adopt the digital format for B2G contracts immediately to avoid exclusion from public tenders.

Penalties for Non-Compliance

The Bulgarian government has introduced a strict penalty regime to ensure high adoption rates and data accuracy. Non-compliance is not merely about missing deadlines but also about submitting incorrect XML data structures.

The Bulgarian government has introduced a strict penalty regime to ensure high adoption rates and data accuracy. Non-compliance is not merely about missing deadlines but also about submitting incorrect XML data structures. The current penalty structure is as follows:

• Isolated Errors: BGN 500 per invoice for clerical errors in mandatory fields.
• Systematic Non-compliance: Up to BGN 10,000 for entities failing to use the NRA-approved system for B2G transactions.
• Delayed Reporting: Fines proportional to the VAT amount due, often ranging from 25% to 100% of the tax value.

Infrastructure: How to Connect to the Bulgarian NRA

To transmit an e-invoice to the Bulgarian tax authority or a B2B partner, businesses usually employ one of three methods:

To transmit an e-invoice to the Bulgarian tax authority or a B2B partner, businesses usually employ one of three methods:

1. PEPPOL Access Points

By using a certified PEPPOL Access Point, a Bulgarian company can send an invoice directly to the recipient’s software, regardless of the brand. The PEPPOL network acts as a secure "e-delivery" highway.

2. API Integration with NRA Portal

Large corporations often build direct API connections between their ERP systems and the NRA’s technical gateway. This requires significant IT investment and ongoing maintenance to keep up with schema updates.

3. Automated Invoicing Platforms

The most cost-effective method for SMEs is utilizing 3rd-party invoicing software that handles the XML conversion, digital signing, and NRA transmission in the background. This ensures that the 20% standard VAT rate or 9% reduced rate is applied correctly according to current Bulgarian tax law.

VAT Calculations and Reporting in Bulgaria

In Bulgaria, Value Added Tax (VAT) is known as ДДС (DDS).

In Bulgaria, Value Added Tax (VAT) is known as ДДС (DDS). E-invoices must clearly distinguish between the different rates:

• Standard Rate (20%): Applied to most goods and services.
• Reduced Rate (9%): Applied to hotel services, restaurants, and certain books/educational materials.
• Zero Rate (0%): Export of goods outside the EU and intra-community deliveries.

The XML format must include the specific "Tax Category Code" (e.g., S for standard, E for exempt) as defined in the PEPPOL BIS 3.0 documentation. Managing these codes manually is a common source of compliance failure, making automated compliance features indispensable.

Frequently Asked Questions

Is e-invoicing mandatory for all businesses in Bulgaria right now?

Currently, it is not mandatory for all B2B transactions, but the B2G mandate starting in April 2026 will require all companies supplying the public sector to use PEPPOL XML formats. Full B2B mandates are expected by 2027.

Currently, it is not mandatory for all B2B transactions, but the B2G mandate starting in April 2026 will require all companies supplying the public sector to use PEPPOL XML formats. Full B2B mandates are expected by 2027.

What is the standard XML format for Bulgaria?

Bulgaria follows the EU standard EN 16931, specifically the PEPPOL BIS Billing 3. 0 version of UBL 2.

Bulgaria follows the EU standard EN 16931, specifically the PEPPOL BIS Billing 3.0 version of UBL 2.1 XML.

What are the penalties for missing a mandatory e-invoice?

Penalties range from BGN 500 to BGN 10,000 per invoice. In cases of VAT evasion linked to missing invoices, penalties can be much higher based on the tax amount.

Penalties range from BGN 500 to BGN 10,000 per invoice. In cases of VAT evasion linked to missing invoices, penalties can be much higher based on the tax amount.

Does a PDF count as an e-invoice in Bulgaria?

Under the new mandates, a simple PDF is not considered a valid electronic invoice. A valid e-invoice must be a structured data file (XML) that can be processed automatically by computers.

Under the new mandates, a simple PDF is not considered a valid electronic invoice. A valid e-invoice must be a structured data file (XML) that can be processed automatically by computers.

Which authority oversees e-invoicing in Bulgaria?

The National Revenue Agency (NRA), or Национална агенция за приходите, is the primary body responsible for e-invoicing regulations and tax collection.

The National Revenue Agency (NRA), or Национална агенция за приходите, is the primary body responsible for e-invoicing regulations and tax collection.

Are there turnover thresholds for e-invoicing?

The mandate generally applies to all VAT-registered entities, which in Bulgaria currently requires registration if annual turnover exceeds BGN 100,000.

The mandate generally applies to all VAT-registered entities, which in Bulgaria currently requires registration if annual turnover exceeds BGN 100,000.

How can I ensure my software is compliant?

Ensure your software provider supports PEPPOL network transmission and can generate XML files that pass the EN 16931 validation rules used by the Bulgarian NRA.

Ensure your software provider supports PEPPOL network transmission and can generate XML files that pass the EN 16931 validation rules used by the Bulgarian NRA.