OZG-RE Portal: Features, Registration & Best Practices

Germany's OZG-RE Portal is the unified federal platform for submitting electronic invoices to public authorities. Operating under the Online Access Act (OZG), it enables suppliers to transmit XRechnung-compliant invoices through web forms, file uploads, email, or Peppol network to federal administrations and cooperating states.

Key Takeaways

• OZG-RE replaced the legacy ZRE portal as of September 2025 and now serves as the single B2G e-invoicing gateway.
• Suppliers must use a Leitweg-ID to route invoices to the correct government recipient.
• Accepted submission channels include manual web entry, XRechnung XML upload, email transmission, and Peppol network.
• Registration is free and available to all businesses invoicing German federal authorities.
• Only XRechnung-compliant invoices in pure XML format are accepted; PDF invoices are not valid submissions.

What is OZG-RE Portal?

OZG-RE (Onlinezugangsgesetz-konforme Rechnungseingangsplattform) is the centralized invoice reception platform operated by the German federal government's e-invoicing competence center. 

It functions as the primary gateway for receiving, validating, and routing electronic invoices from suppliers to all institutions of the direct federal administration, indirect federal bodies, and cooperating German states.

The platform replaced the legacy ZRE (Central Invoice Submission Portal) following the government's November 2024 consolidation decision to simplify e-invoicing infrastructure and reduce complexity for suppliers. As of September 19, 2025, OZG-RE became the mandatory platform for all federal B2G invoicing.

Germany's E-Invoicing Framework for Public Sector

Germany implemented mandatory e-invoicing for federal government suppliers under EU Directive 2014/55/EU and the national E-Invoicing Ordinance (E-Rechnungsverordnung). 

Federal authorities are required to receive electronic invoices in structured formats, and suppliers invoicing public bodies must transmit their invoices through designated portals. The e-invoicing mandate applies to all suppliers issuing invoices to the direct and indirect federal administration. 

The regulation requires invoices to comply with the XRechnung standard, a German implementation of the European EN 16931 semantic data model. Invoices must be submitted electronically through official channels, with the Leitweg-ID serving as the unique routing identifier for each recipient authority.

Key Features of OZG-RE

The OZG-RE Portal offers multiple submission channels, strict validation mechanisms, and enterprise-grade security to ensure compliant and efficient invoice processing.

1. Multi-Channel Submission Architecture

OZG-RE accommodates diverse business infrastructure requirements through four distinct invoice submission channels.

2. XRechnung Standard Compliance

OZG-RE exclusively accepts XRechnung-compliant invoices. XRechnung is the German-specific e-invoice format built upon the European EN 16931 standard. 

The current specification (Version 3.0) requires 107 data elements across 11 semantic data groups, with specific mandatory fields for B2G transmission.

Mandatory data elements include:

• Invoice number, issue date, and due date
• Supplier identification with VAT ID or tax number
• Leitweg-ID in the Buyer Reference field (BT-10)
• Complete line item details with quantities, prices, and VAT classification
• Payment method and banking information
• Currency code (EUR required for federal invoicing)

3. Leitweg-ID Routing System

The Leitweg-ID is the cornerstone of the OZG-RE addressing mechanism. It functions as a unique hierarchical identifier that automatically routes invoices to correct administrative recipients across Germany's federal and state structures.

The Leitweg-ID format follows a specific structure:

• Level Code (2 digits): Identifies federal administration (99) or individual states (91-16)
• Regional Identifier (up to 11 digits): Specifies the organizational unit
• Address Code (up to 30 alphanumeric characters): Defines the recipient department
• Checksum (2 digits): Validates the identifier accuracy

Suppliers must obtain the correct Leitweg-ID from the ordering authority during contract negotiation or through the central Leitweg-ID register before invoice submission.

4. Invoice Validation Pipeline

OZG-RE implements comprehensive validation to ensure submission quality and recipient system compatibility.

The validation process includes:

• Technical validation: XML well-formedness, XSD schema compliance, UTF-8 encoding, and file size limits
• Semantic validation: Mandatory field completion, Leitweg-ID format verification, VAT ID presence, and date format compliance
• Business rule validation: Invoice number uniqueness, amount calculation verification, and currency code validation

Failed validations trigger immediate notifications with specific error codes and detailed explanations, allowing suppliers to correct and resubmit invoices without penalties.

5. Portal Security and Authentication

OZG-RE implements enterprise-grade security measures protecting sensitive business and government data.

Authentication methods include:

• ELSTER account integration with single sign-on for companies with existing German tax registration
• Email and password authentication with mandatory two-factor verification
• Session timeout after 30 minutes of inactivity
• Account lockout after 5 failed login attempts

Data protection features include TLS 1.2+ encryption for all communications, AES-256 encryption for stored invoices, and mandatory antivirus scanning of all file uploads.

Who Needs to Use OZG-RE Portal?

OZG-RE registration is mandatory for all businesses, service providers, and organizations that issue invoices to German federal authorities and cooperating state administrations.

Mandatory User Categories

The following entities must use OZG-RE for B2G invoicing:

• Service providers: Consulting firms, IT service providers, advertising agencies, professional practices
• Product suppliers: Wholesalers, manufacturers, equipment suppliers, software vendors
• Construction and engineering: General contractors, subcontractors, design professionals
• Facility services: Cleaning services, maintenance contractors, security providers
• Healthcare suppliers: Medical equipment suppliers, pharmaceutical distributors
• Digital services: Cloud providers, software developers, IT support

Applicability Criteria for OZG-RE Portal Registration

OZG-RE registration applies when:

• The invoice recipient is a German federal authority or cooperating state/municipal authority
• The supplier has accepted a government contract or purchase order
• The Leitweg-ID has been provided by the purchasing authority
• The invoice amount exceeds the €250 threshold (below-threshold invoices may have alternatives)

Exemptions and Exceptions for OZG-RE Portal Registration

Certain organizations may qualify for exemptions from mandatory OZG-RE use:

• Micro-enterprises with fewer than 10 employees and under €2 million revenue may request administrative burden exemptions
• Contracts with explicit provisions permitting alternative invoicing methods
• SEPA direct debit or government procurement card arrangements may have alternative requirements

OZG-RE Portal Registrations

Registration for OZG-RE is free and straightforward for all suppliers. The process involves account creation, company information entry, and email verification.

Pre-Registration Requirements

Before initiating registration, organizations must prepare the following documentation:

• Legal business name as registered in official records
• VAT ID number or tax identification number
• Complete business address with postal code
• Authorized contact person with email and phone number
• List of government authorities requiring invoice submission
• Corresponding Leitweg-IDs for each authority

How to Register For OZG-RE Portal: Step-by-Step Process

The registration process follows six sequential steps.

Step 1: Portal Access: 

Navigate to the official OZG-RE portal and select "Create new user account" on the homepage. Accept the Terms of Use and Data Privacy Policy to proceed.

Step 2: Company Information Entry

Complete the company registration form with legal entity information including:

Step 3: User Account Information

Enter personal information for the account administrator:

• First and last name
• Email address (used for activation and notifications)
• Phone number for verification
• Role and department within the organization

Step 4: Password Creation

Create a secure password meeting the following requirements:

• Minimum 12 characters
• At least one uppercase letter, one lowercase letter, one number, and one special character
• No three consecutive identical characters

Step 5: Review and Submission

Verify all entered information on the summary screen. Make corrections if needed, then click "Create Account" to submit the registration.

Step 6: Email Verification

Check the registered email for an activation link (valid for 30 minutes). Click the link to complete account activation and enable login access.

Post-Registration Configuration

After successful registration, configure the account for efficient invoice submission:

• Add additional users with appropriate permission levels (Admin, Submitter, or Viewer)
• Create a Leitweg-ID database for frequently invoiced authorities
• Configure notification preferences for submission confirmations and validation alerts

How to Send an Invoice via OZG-RE Portal

Invoice submission through OZG-RE requires proper preparation, accurate data entry, and verification before final transmission.

Pre-Submission Checklist

Before initiating submission, verify the following requirements:

• Unique invoice number within your organization
• Invoice date and due date in YYYY-MM-DD format
• Complete line items with descriptions, quantities, and prices
• Correct VAT calculation (19% standard, 7% reduced, or applicable rate)
• Valid Leitweg-ID obtained from the recipient authority
• Total invoice amount matching the sum of line items

1. Sending e-Invoices via Web Form Submission Method: Step by Step Guide

The web form submission method is ideal for organizations with low invoice volumes.

Step 1: Access Invoice Creation Form: 
Log into OZG-RE and click "Create New Invoice" from the dashboard.

Step 2: Enter Initial Data
Select XRechnung 3.0 as the data format. Choose the invoice type (Commercial Invoice, Correction Note, or Credit Note). Enter the Leitweg-ID in the Buyer Reference field.

Step 3: Complete Invoice Header Information
Enter supplier details, invoice number, invoice date, and payment terms. Verify that your company name and VAT ID match official registration records.

Step 4: Add Line Items
For each item or service:

• Enter a clear description of the goods or services
• Specify quantity and unit of measure
• Enter unit price (net of tax)
• Select the applicable VAT category and rate

Step 5: Review and Validate
The system displays a complete invoice preview with validation status. Review all information for accuracy. Address any validation errors shown in red before proceeding.

Step 6: Submit and Confirm
Click "Submit Invoice" to transmit the invoice. The system generates a unique reference number and timestamp as confirmation of successful submission.

2. Sending e-Invoices via XRechnung File Upload Method

For organizations using accounting software with XRechnung export functionality:

1. Export the invoice from your ERP or accounting system in XRechnung 3.0 XML format
2. Log into OZG-RE and select "Upload XRechnung File"
3. Select your XML file (maximum 50 MB including attachments)
4. Attach supporting documents if required (up to 10 files)
5. Submit and await validation confirmation

3. Sending e-Invoices via Peppol Network Transmission

High-volume suppliers can use Peppol network transmission through accredited service providers:

• Select a German Peppol Authority-accredited service provider
• Configure system integration with your ERP or accounting software
• Transmit invoices automatically using participant identifiers
• Receive real-time validation and delivery confirmation

Benefits of Using OZG-RE

OZG-RE delivers significant advantages for suppliers invoicing German federal authorities.

Additional operational benefits include:

• Elimination of paper-based invoicing and postal delays
• Reduced rejection rates through pre-submission validation
• Standardized format ensuring consistent invoice interpretation
• Integration capability with existing ERP and accounting systems

Difference Between OZG-RE and ZRE Portals

Understanding the distinction between OZG-RE and the legacy ZRE system clarifies the current invoicing landscape.

Suppliers with existing ZRE accounts were automatically migrated to OZG-RE. 

Best Practices for Using OZG-RE

Following best practices ensures smooth invoice processing and minimizes rejection rates.

1. Leitweg-ID Management

• Maintain an internal database of Leitweg-IDs mapped to customer accounts
• Verify Leitweg-IDs through the central register before first submission
• Implement validation routines checking format compliance
• Schedule quarterly reviews for high-volume recipients to identify changes

2. Invoice Data Quality

• Use consistent naming conventions matching official business registration
• Ensure VAT calculations are accurate before submission
• Include clear, detailed descriptions for each line item
• Verify date formats follow YYYY-MM-DD ISO 8601 standard

3. Submission Process Optimization

• Test submissions in the portal's test environment before production use
• Establish internal review procedures before final submission
• Monitor submission history for patterns in validation failures
• Respond promptly to any requests for additional information

4. Documentation and Compliance

• Retain copies of all submitted invoices and confirmations for 10 years
• Document Leitweg-ID sources in procurement records for audit purposes
• Train accounting staff on XRechnung requirements and portal procedures
• Stay informed about OZG-RE updates and specification changes

Conclusion

For businesses supplying goods or services to German federal authorities, OZG-RE is the mandatory channel for invoice submission. The portal's multi-channel architecture accommodates diverse technical capabilities, from manual web entry to fully automated Peppol transmission. 

Maintaining accurate Leitweg-ID records, ensuring XRechnung compliance, and implementing validation checks before submission are essential for avoiding rejections and ensuring timely payment processing. 

As Germany continues to advance its digital administration goals, suppliers with robust e-invoicing processes will be better positioned for efficient public sector engagement.