E-Invoice Transmission Methods in Germany: Complete Guide

Under Germany’s e-invoicing framework, businesses can transmit e-invoices through web submission, upload, email, Peppol or De-Mail. The right method depends on the invoice volume, level of automation, buyer requirement and the type of the transaction.

E-Invoice Transmission Methods in Germany

When it comes to e-invoicing in Germany, the transmission method you choose can make or break your compliance journey. 

1. Web Submission

Web submission is one of the easiest methods of communicating e-invoices in Germany, particularly for those companies not using dedicated e-invoicing or ERP systems. It allows suppliers to generate and issue invoices within the same official web portal.

How it Works

• Businesses access and log in to the designated portal (e.g., OZG-RE)
• Invoice data is manually entered into structured web forms.
• Key fields typically include:Buyer reference (Leitweg-ID), Supplier and recipient details, Invoice line items, VAT, and total amounts
• The system performs real-time checks to ensure completion and formatting and automatically creates and sends the e-invoice to the recipient.

Key Advantages

• No need for any specialized software
• Cost-effective, as there are no licensing or integration costs involved
• Built-in checks help reduce errors before submission.
• Most effective for limited or occasional invoicing activities

Limitations

• Manual data input can limit the ability to efficiently handle growing volumes.
• It also increases the possibility of errors in invoice information, including incorrect amounts or details.

Use Cases

Businesses in the early stages of adopting e-invoicing, along with small or occasional suppliers, may find web submission more suitable due to its straightforward setup and low complexity.

2. Upload

The upload method offers a partly automated solution for businesses that can already create compliant e-invoices through their internal systems but choose to submit them manually via a portal. It sits between fully manual entry and end-to-end automated transmission.

How it Works

• Invoice data is prepared using internal systems like ERP or accounting tools.
• It is then converted into a compliant format, usually XRechnung (XML-based).
• The file is uploaded through a portal (for example, OZG-RE) for submission.
  • Drag-and-drop, or
  • File selection tools
• The system performs multi-level validation, including:
  • Format and structure checks
  • Business rule validation
  • VAT and mandatory field verification
• Once validated, the invoice is accepted and routed to the recipient.

Key Advantages

• Removes the need for repetitive input, hence less human error
• Helps keep internal financial data consistent with submitted invoices
• Makes it easier to process several invoices in a single cycle
• Fits easily into current accounting setups with minimal impact on workflows 

Limitations

• Errors require correction in the source system and re-uploading.
• No direct integration with archiving or workflow systems

File and System Considerations

• Files must comply with EN 16931 standards (XRechnung format).
• Size and attachment limits apply within the portal.
• Attachments are typically embedded within the XML file.

Use Cases

The upload method suits businesses with existing invoicing systems and moderate transaction volumes who want better accuracy without the complexity of full automation.

3. Email

Among the available e-invoice transmission methods in Germany, email remains one of the most accessible and widely adopted options for businesses of all sizes. It relies on your current communication infrastructure yet can also handle the structured format of the invoice. This method could be a great trade-off between compliance and simplicity, especially for the businesses that don't need to produce a lot of invoices.

How it Works

• E-invoices are generated in compliant formats such as XRechnung or ZUGFeRD.
• The invoice is sent as an XML attachment via email.
• For B2G a designated portal email address is used with each email containing only one invoice file.
• For B2B businesses exchange invoices via dedicated email inboxes.
• The system or recipient validates the invoice for:Format compliance, Mandatory data fields, and VAT accuracy

Key Advantages

• No additional infrastructure is required; uses existing email systems
• Supports direct exchange between trading partners
• Cost-effective with minimal setup requirements
• Appropriate for moderate invoice quantities

Limitations

• No guaranteed proof of delivery or receipt
• File size restrictions may apply to attachments.

Security Considerations

• Standard email may lack end-to-end encryption.
• Businesses should implement:
  • TLS encryption for secure transmission
  • Optional digital signatures for authenticity
• Additional controls (e.g., SPF, DKIM) help prevent fraud.

Use Cases

Email is a good choice for companies with a low to moderate number of invoices and fixed partners, where ease and flexibility are more critical than complete automation.

4. Peppol

PEPPOL (Pan-European Public Procurement Online) is the most advanced and future-ready transmission method available in Germany. It operates through a standardized, secure network that enables fully automated invoice exchange between businesses. It removes the need for manual handling and the complexity of managing multiple separate connections.

How it Works

• Peppol operates on a four-corner model: Sender (supplier), Sender’s Access Point, Receiver’s Access Point, Recipient (buyer)
• Businesses connect to the network through a certified access point provider.
• Invoices are transmitted using standardized protocols (AS4).
• Routing is based on a unique Peppol ID (e.g., VAT number or Leitweg ID)
• The network automatically handles: validation, secure transmission and delivery confirmation

Key Advantages

• Enables fully automated, machine-to-machine communication
• Provides secure and reliable delivery with confirmation receipts
• Supports high invoice volumes and scalability
• Standardized across countries, making it ideal for cross-border transactions

Limitations

• Requires initial setup and integration with systems
• Involves ongoing service provider costs

Technical and Compliance Aspects

• Uses Peppol BIS 3.0 format aligned with EN 16931 standards
• Supports German formats such as XRechnung
• Requires registration of a Peppol ID for routing
• Ensures secure and encrypted data exchange

Use Cases

Peppol is generally a good fit for medium to large businesses that deal with high volumes of invoices, especially those involved in public procurement (B2G) or cross-border EU trade. 

5. De-Mail

De-Mail is a secure digital communication system in Germany designed to exchange confidential and legally recognized messages between businesses, individuals, and public authorities. It is designed to offer a higher level of security and authentication, as every message is tied to a verified identity, making it far more trustworthy than conventional email for sensitive business communication.

How it Works

• Businesses use De-Mail accounts provided by certified service providers.
• Messages are transmitted through secure, encrypted channels.
• Sender identity is verified and authenticated for message integrity.
• Each transmission provides proof of delivery and timestamping, supporting legal validity.

Key Advantages

• High level of security and encryption, suitable for sensitive data
• Provides authenticated communication, reducing fraud risks
• Offers legal certainty through verifiable delivery and sender identity
• Operates within a regulated framework approved by German authorities

Limitations

• May involve additional costs per message or subscription fees
• Integration with ERP or invoicing systems can be quite complicated.

Use Cases

De-Mail is mainly used when secure communication with government authorities is needed or when a higher level of legal reliability is important. It is not commonly used for large volumes or automated invoicing, but rather for situations where security and verification are critical.

Here is the official BMF glossary on e-Invoice Transmission Methods

How Businesses Should Choose a Transmission Method

Before you get to the selection criteria, access your invoice volume, technical capability, trading partner requirements, and cost considerations. It is important to note that the right fit for B2G transactions may also look quite different from what works best for B2B.

For B2G (Government Invoicing):

• Up to 10 invoices/month: Manual web-based submission remains the most practical, as it requires no system integration.
• 10–100 invoices/month: Upload-based methods are more efficient where ERP or accounting systems can generate compliant files.
• 100+ invoices/month: Peppol is typically the preferred option due to its automation, scalability, and less manual effort.

For B2B Transactions:

Customer requirements often determine the transmission method, especially for larger buyers.

• Up to 50 invoices/month: Email offers sufficient flexibility.
• 50–500 invoices/month: A combined approach (email and Peppol) provides balance.
• 500+ invoices/month: Fully automated solutions such as Peppol or EDI are more appropriate.

Conclusion

Germany’s e-invoicing mandate promotes standardized, digitally structured invoice formats to enable automation and strengthen compliance frameworks. Given these requirements, a multi-channel setup is often more practical, as it allows businesses to handle diverse operational and partner demands. As implementation progresses, the right system setup can lead to more streamlined operations and better financial governance.