What Is AS2 and Why Is It Important for EDI?

AS2 (Applicability Statement 2) is a popular protocol for secure and reliable transmission of structured business data over the internet – including EDI documents. It enables encryption, digital signatures, and delivery receipts (MDNs), making it ideal for B2B communication across industries.

Key takeaways

AS2 transfers EDI and other structured business data over HTTP or HTTPS with encryption and digital signatures.
MDNs confirm whether a message was received successfully and help support reliable, auditable exchange.
AS2 can be efficient and cost-effective, but partner setup, certificate management, and firewall configuration still require ongoing attention.

No time to read?

Watch our video!

AS2 is an HTTP-based protocol for securely exchanging structured business data, including EDI messages, over the internet. It uses encryption, digital signatures, and message receipts called MDNs to help trading partners send data directly, confirm delivery, and protect message integrity.

For organizations that exchange EDI with customers, suppliers, and partners, AS2 provides a widely used internet-based option for secure and traceable B2B communication. SEEBURGER supports AS2 in broader B2B/EDI integration scenarios, including managed routing and cloud-based connection options.

AS2 creates a direct connection between a sender and a receiver over the internet. The sending system prepares the data, encrypts and signs it, and sends it over HTTP or HTTPS. The receiving system decrypts the message, verifies the signature, and returns an MDN to confirm successful delivery.

The sending system prepares the business data and applies encryption and a digital signature.
The secured message is transmitted over HTTP or HTTPS.
The receiving system decrypts the message and verifies the signature.
The receiving system sends an MDN back to confirm successful delivery.

One AS2 identification and one certificate per participant
The public keys for all certificates used by trading partners
AS2-capable software

Each participant needs a unique identifier and certificate information so messages can be routed correctly and verified securely between trading partners.

What are AS2 certificates?

AS2 certificates help establish trusted, secure communication between trading partners. They can be created with in-house software or obtained from a certification authority. A valid certificate helps avoid delays or rejections caused by invalid credentials, while self-signed certificates can trigger security warnings.

What is an AS2 MDN?

An MDN, or Message Disposition Notification, is the receipt returned after a message is delivered. It confirms whether the AS2 interchange completed successfully and whether the message was received intact by the intended recipient.

A GLN, or Global Location Number, is a unique identifier of up to 13 digits used to identify a company or business location. It can help route AS2 exchanges correctly between trading partners.

Main features

Encryption and digital signatures for confidentiality, authenticity, and integrity
MDNs and non-repudiation support for acknowledged delivery
Compression to reduce message size
Support for EDI, XML, plain text, and binary files
Standardized headers, timestamping, and synchronous or asynchronous communication options

Common message types

EDI data messages containing business documents such as purchase orders, invoices, or shipping notices
MDNs, including synchronous and asynchronous acknowledgments
Signed, encrypted, compressed, and signed-and-encrypted messages
Receipt requests that ask a recipient to return an MDN

AS2 is widely used across industries including retail, logistics and transportation, healthcare and pharma, automotive, financial services, consumer packaged goods, and utilities. It is also used broadly in North America, Europe, and Asia-Pacific.

Benefits	Challenges
High security through encryption and digital signatures	Point-to-point partner management and key exchange can become time-intensive
Internet-based transmission can lower communication costs	Firewall configuration may require open ports
Synchronous communication can enable real-time responses	Certificates must be renewed to avoid expiry-related errors
Broad use across industries supports interoperability	Scaling many partner connections increases operational overhead

SEEBURGER supports AS2 operations with managed routing and cloud-based connection options for broader B2B/EDI integration requirements.

White Paper

Accelerate and Automate Business Driven Innovation with Integration

Read now

What does AS2 stand for?

AS2 stands for Applicability Statement 2, an HTTP-based protocol for securely transmitting structured business data over the internet.

How does AS2 help secure EDI data exchange?

AS2 uses encryption, digital signatures, and MDNs to help protect message confidentiality, verify integrity, and confirm delivery.

What is an AS2 MDN?

An AS2 MDN is the receipt returned to the sender after delivery, confirming whether the interchange completed successfully and whether the message was received intact.

What do trading partners need before they can exchange AS2 messages?

They need AS2-capable software, certificate information, and the partner identification and key details needed to route and verify messages securely.

Which data formats can AS2 transmit?

AS2 can transmit EDI, XML, plain text, and binary files.

Why can AS2 become complex to manage at scale?

AS2 becomes more complex to manage as the number of trading partners grows because partner onboarding, key exchange, firewall configuration, and certificate renewal all require ongoing attention.

Alexander Schmidt

Product Manager Utilities

SEEBURGER

Good to Know

EDI allows electronic interchange of business information using standardized protocols and formats. These paperless business-to-business (B2B) transactions make EDI the standard of automating supply chain management (SCM) in many different industries.

All Industries, B2B/EDI

What Are EDI Benefits?