What is an Electronic Registered Delivery Service (ERDS)

Registered email and other forms of legally valid digital communication are based on a common legal and technical framework: the Electronic Registered Delivery Service, or ERDS.

These services allow users to send and receive information electronically while ensuring that the sending, content, and delivery are authenticated and protected against tampering.

In this article, we explain what an ERDS is, what makes it legally valid, and why it is the foundation of registered email.

What is an Electronic Registered Delivery Service (ERDS)

An ERDS is a service regulated by the EU Regulation (No 910/2014), better known as eIDAS, which ensures that data sent electronically between two parties is transmitted securely and verifiably.

Article 3.36 of the Regulation defines it as:

“A service that makes it possible to transmit data between third parties by electronic means and provides evidence relating to the handling of the transmitted data, including proof of sending and receipt, while protecting the data against loss, theft, damage or any unauthorised alterations.”

In practice, this means the provider acts as a trusted third party, generating legally admissible evidence for every communication.

Types of services: qualified and non-qualified

The eIDAS Regulation distinguishes between two categories:

• Qualified Electronic Registered Delivery Service (QERDS):
  This model complies with the most stringent requirements of eIDAS and involves verified identification of all parties. However, that same requirement introduces friction and incompatibility with standard email, limiting its practical use in everyday communication.

• Non-qualified ERDS:
  This category does not require registration in a Trusted List (TSL) and is legally valid as long as it provides verifiable evidence of sending, content, and delivery. Its simplicity and usability are its greatest strengths, adding strong evidentiary value to conventional email.

The registered email service from eEvidence falls within this second category: it fully complies with the eIDAS Regulation and provides legally admissible proof of communication, without the operational complexity of a qualified service.

What an ERDS guarantees

An Electronic Registered Delivery Service ensures three essential elements:

1. Proof of origin – who sent the message and from which address.
2. Proof of content – the exact information that was transmitted.
3. Proof of delivery – when and to whom the message was delivered, even if it was not opened.

It also guarantees data integrity (that the content was not modified) and protection against unauthorised access.

Why ERDS is key to digital transformation

ERDS is the foundation of services such as registered email, registered SMS, and electronic signature.

Thanks to ERDS, companies can:

• Replace paper-based processes with digital equivalents that have full legal validity.
• Reduce costs and delays in notifications, claims, and formal communications.
• Ensure traceability and regulatory compliance across digital workflows.

In an increasingly digital world, ERDS-based trust services strengthen the legal certainty of online transactions and professional communications.

Legal framework: eIDAS Regulation and future evolution

The EU Regulation No 910/2014 (eIDAS) established the current framework for digital trust across Europe.

With the upcoming eIDAS 2.0, interoperability between providers will be reinforced through new standards such as ETSI EN 319 522, designed to enable cross-border communication between different ERDS providers within the EU.

This means that in the near future, users will be able to send a registered email through a provider in Spain and have it received in another provider’s system in Germany or Italy, maintaining the same legal validity.

Frequently Asked Questions (FAQ)

Does an ERDS have legal validity even if it is not “qualified”?

Yes. Article 43.1 of the eIDAS Regulation explicitly states that a registered delivery service cannot be denied legal effect or admissibility as evidence solely because it is not qualified.

What is the difference between ERDS and registered email?

Registered email is a practical implementation of ERDS — it uses email as the communication channel while certifying the sending, content, and delivery of messages.

What is the role of the service provider?

The provider acts as a trusted third party. It records all technical evidence of the transmission and generates a digitally signed document with a qualified timestamp, serving as verifiable proof.

How does an ERDS ensure data protection?

Providers must apply strong technical and organisational measures to guarantee confidentiality, integrity, and traceability — in full compliance with the General Data Protection Regulation (GDPR).

Conclusion

Electronic Registered Delivery Services (ERDS) form the foundation of secure, legally valid digital communication.

They make it possible to prove who sent what, when, and to whom — ensuring authenticity, integrity, and traceability.

In an era where digital trust is essential, solutions such as the registered email service from eEvidence provide companies and professionals with a robust, efficient, and fully legal way to communicate with confidence.