Use Cases
Implement e-invoicing in compliance with legal requirements – without changing your systems
The introduction of electronic invoicing (e-invoicing) is affecting almost every company in Germany. Legal requirements and European standards are gradually making it a mandatory part of accounting. To implement e-invoicing legally, a solution is needed that meets legal requirements and integrates with existing systems.
Consequently, many companies are asking themselves: 'How can we implement e-invoicing in a legally compliant manner without replacing our entire existing system?'
We answer precisely this question. This article demonstrates how e-invoices can be created, validated, transmitted and processed automatically, in compliance with standards and integrated into existing systems.
The topics at a glance:
- What is an e-invoice?
- E-invoice formats: XRechnung and ZUGFeRD
- When will the e-invoicing requirements come into effect, and who will it affect?
- Typical challenges in companies
- Our solution: E-invoice with Syncler
- Technical connection: Flexible and open to all systems
- Added value for your company
- Archiving: GoBD-compliant and audit-proof
- Combination with other systems
- Conclusion: E-invoicing as an opportunity
- FAQ
What is an e-invoice?
An e-invoice is neither a scanned paper invoice nor a simple PDF document. It is based on a structured electronic data format that enables automatic processing by IT systems. This is based on the EU standard EN 16931, which defines the electronic exchange of invoice data within the EU internal market.
Key features:
- Structured data record (machine-readable)
- Automatic processing without media breaks
- Mandatory fields in accordance with the standard
- Optional fields that can be added within the standard specifications
- >Country-specific characteristics based on CIUS (Core Invoice Usage Specifications)
Important note: E-invoicing is just the beginning. With E-invoicing is just the beginning. With the E-invoicing Act, the exchange of digital documents has been incorporated into national law, and other types of electronic documents will follow.
E-invoice formats: XRechnung and ZUGFeRD
Two formats have become established in Germany:
- XRechnung: a pure XML format that is machine-readable
- ZUGFeRD: a combined format consisting of machine-readable XML data and human-readable PDF
Many companies are asking themselves: Which format is the right one: XRechnung or ZUGFeRD?
XRechnung is often used in the public sector, while ZUGFeRD is used more commonly in the B2B sector.
The Syncler e-invoice connector supports both formats and can be flexibly expanded to accommodate further standards.
When will the e-invoicing requirement come into effect, and who will if affect?
The e-invoicing requirement will be introduced in stages in Germany.
- From 2027: mandatory for large companies with a turnover of more than €800,000
- From 2028: mandatory for all other companies (except small businesses)
- Exceptions: invoices to end consumers (B2C) and small amounts
Important: All companies must be able to receive e-invoices from 2025.
This means that, even if they are not obliged to issue e-invoices, companies must have the technical capability receive them.
Typical challenges in companies
Many companies encounter similar issues when implementing e-invoicing:
- Exisiting ERP or accounting systems do not support e-invoices
- Manual conversions cause media breaks
- Uncertainity regarding legal compliance
- Validation requirements are unclear
- High cost of adapting to new legal requirements
In most cases, a complete system change is expensive, risky and unnecessary.
Our solution: E-invoice with Syncler
The Syncler e-invoice connector acts as a central integration and automation layer between existing systems and the world of e-invoicing.
Key features:
- Creation, reading and writing of e-invoices
- Processing of XML files or XML data from PDF attachments
- Sending as pure XML or XML with embedded PDF
- Fully automated processing without manual intermediate steps
- Flexible integration into existing systems
Integrated validation:
Each e-invoice is automatically checked using the connected Validool tool. Errors are detected before invoices are sent or posted. This ensures legal compliance, minimises rejections and provides security in the invoicing process.
The price of Validool is included in the Syncler e-invoice connector.
Technical connection: Flexible and open to all systems
The connector can be used to connect to different sources and destinations:
- Local directories (on-premises)
- FTP servers
- Direct transfer via Syncler API (SaveXML endpoint)
This makes the solution suitable for classic on-premises scenarios and hybrid integration approaches.
Added value for companies:
1. No system change is necessary
Existing ERP, CRM or accounting systems can continue to be used.
2. Automation instead of pure format conversion
E-invoices are automatically generated, validated and processed, not just converted. Follow-up processes are triggered directly.
3. High degree of automation with low integration effort
Syncler acts as an integration layer between existing systems.
4. Increased efficiency
Faster invoice processing, shorter payment cycles and less manual checking.
5. Future-proof
Ongoing adjustments to regulatory requirements ensure the solution remains compliant in the long term.
Archiving: GoBD-compliant and audit-proof
Like paper invoices, e-invoices must:
- Be archived in accordance with GoBD
- Be stored in an unalterable form
- Remain machine-readable
- Be retained for 10 years
The structured layout of e-invoices supports audit-proof archiving and makes tax audits considerably easier.
Combination with other systems
The e-invoice connector is at its most effective when used alongside other integrations.
- Mail connector: Automatically processes incoming invoices from emails
- File or FTP connector: Time-controlled import and storage of invoices
- Office software connector: Transfer to ERP or accounting systems
This creates a continuous, automated process chain.
Conclusion: E-invoicing is an opportunity, not an obligation
E-invoicing is a strategic step towards digital business processes, not just a legal obligation.
The Syncler e-invoicing connector enables companies to meet legal requirements, technical standards, validation specifications and archiving obligations. They can do so without changing systems, experiencing media discontinuity or introducing unnecessary complexity.
Acting now will ensure legal compliance and increase the efficiency, transparency and future viability of processes.
Would you like to know how e-invoicing can be integrated into your existing system landscape? We would be happy to advise you individually.
FAQ
Our ERP system does not support e-invoicing. Do we now have to change our software?
No. A complete system change is usually not necessary. With the Syncler e-invoicing connector, everything can be integrated into the existing system.
How should e-invoices be archived?
E-invoices must be archived in accordance with the GoBD. This means unalterable storage, machine readability and a retention period of 10 years. Simply saving them as files is not sufficient unless there is an audit-proof archiving structure in place. Archiving must comply with legal requirements, as with paper invoices.
Does the e-invoicing requirement also apply to invoices for private customers (B2C)?
No, it basically applies to the B2B sector, i.e. invoices between companies. Invoices to end consumers (B2C) are exempt from this requirement. Nevertheless, companies must be technically capable of receiving e-invoices from 2025 onwards.
XRechnung or ZUGFeRD?
Whether to use XRechnung or ZUGFeRD depends on the area of application. XRechnung is a pure XML format. ZUGFeRD combines a readable PDF with an embedded XML invoice. The most suitable option depends on the requirements of your business partners and your system landscape.
Why is a standard PDF not sufficient for an e-invoice?
A normal PDF document is legally considered an e-invoice. In order to be processed automatically, an e-invoice must be structured XML invoice in accordance with EU standard EN 16931.