We have compiled an overview of the most important information below.

1. Valid formats

Valid formats must comply with the European standard for electronic invoicing and the list of corresponding syntaxes in accordance with Directive 2014/55/EU (and therefore CEN standard EN 16931). The e-invoice must use a standardised format (such as ZUGFeRD or XRechnung).

– XRechnung: This is the standardised XML-based format used by the public sector. It is based on the European standard for electronic invoicing (EN 16931).

– ZUGFeRD: This is a hybrid format that combines both an XML data structure and a PDF file with embedded structured invoice data. ZUGFeRD has the advantage that it is a hybrid invoice format. This means that it includes an image file (PDF) AND a structured part (XML) so that these invoices can be read without further preparation.

2. exceptions

– Small value invoices up to €250 (Section 33 UStDV)

– Tickets (§ 34 UStDV)

3. transitional regulations

– 2025 until 31.12.2026: Alternative invoicing in paper or other electronic format is permitted àif the invoice recipient agrees.
(§27 para. 38 no. 1 UStG)

– 2026 to 31.12.2027: Alternative invoicing in paper or other electronic format remains permissible àif the invoice recipient agrees and àthe total turnover in the previous year does not exceed EUR 800,000.
(§27 para. 38 no. 2 UStG)

– 2026 to 31.12.2027: The use of electronic data interchange (EDI procedure) is still permitted à if the recipient agrees. This is independent of the previous year’s turnover.
(§27 para. 39 no. 3 UStG)

– From 2028, the requirements of the e-invoice must be implemented

4. electronic transmission of the invoice

The e-invoice must be transmitted via a secure channel. It is sufficient if the invoice recipient provides an email inbox (BMF letter dated 15 October 2024 para. 40).

5. Invoice data structure and mandatory information

E-invoices must contain certain legally required information that is defined in the EU standard for electronic invoices (EN 16931). This includes, for example

– Name and address of the invoicing party

– Name and address of the invoice recipient

– A unique invoice number

– The invoice date

– The goods or services supplied with the corresponding amounts and tax rates

– The amount of VAT and the net total

6. digital signature and authentication

No digital signature is required for each individual e-invoice, but companies must ensure that the invoice remains authentic and unaltered.

7. invoice archiving

Companies must archive e-invoices for the legally prescribed period of 8 years. These archived invoices must be kept accessible and unaltered at all times.

Archiving must take place in electronic form. In the case of e-invoices, the structured part (=XML) must be archived and it must be ensured that the invoices are available at all times in a machine-readable and fully legible format.

8. Technical implementation and software

Companies must ensure that their accounting and invoicing software is capable of generating, transmitting and receiving e-invoices. Portolan therefore offers solutions based on the Series i for receiving e-invoices. The ESB (eInvoice Support Basis) module covers the reading, visualisation and archiving of e-invoices. Based on this, ESX (eInvoice Support Extended) goes even further and enables the direct processing of e-invoices in EVM FIA. The imported data is transferred to a data entry screen where it can be checked and completed directly.

As a comprehensive solution, Portolan, together with Jobrouter, offers a digitisation platform with which the entire process of e-invoicing and transmission can be automated. Of course, this digitalisation platform can also be used to map processes that go far beyond the processing of e-invoices.

9. challenges

Data quality and consistency. Incorrect or incomplete data can lead to problems when processing e-invoices. Data cleansing is therefore strongly recommended. Implement data validation and cleansing.

The electronic processing of incoming invoices also requires an adjustment of internal processes and workflows. Employees must therefore be trained accordingly in order to be able to use the new systems and processes effectively.

Technology in the field of e-invoicing is constantly evolving. Experience shows that adjustments to formats are to be expected. Companies must therefore be flexible in adapting their processes to the new circumstances

The introduction of electronic invoice receipt usually takes place in co-operation with a software partner, so it is important that communication works smoothly.

10. advantages of the e-invoice

The advantages of e-invoicing are manifold and affect both the efficiency of internal processes and relationships with business partners.

The most important advantages include

– Cost savings: By automating the invoicing process, companies can save considerable costs. Paper, printing and dispatch are eliminated and the processing time for invoices is drastically reduced.

– Error reduction: Manual entries are prone to errors. E-invoices minimise the risk of errors as they can be processed automatically. This leads to greater accuracy and fewer queries.

– Faster payment processing: E-invoices enable faster processing and authorisation, resulting in faster payment processing. This improves cash flow and liquidity.

11. Outlook and conclusion

The implementation of e-invoicing is crucial for future communication with the tax authorities. In many European countries, it has been standard practice for years for all outgoing invoices to be sent to the tax authorities in digital form. In Germany, too, the e-invoice will form the basis for a similar system. It is therefore essential to approach the introduction of e-invoicing systematically and strategically in order to be optimally prepared for the coming requirements. As your software provider, we support you in making this transition smooth and future-proofing your company.