What is AS2?
What is AS2? It is a protocol for sending EDI messages securely over the internet. Every message is encrypted, signed and acknowledged.
By Vincent Rosenkranz, Sales & Marketing Manager at BESITEC · Updated 9 Nov 2026
In short. Applicability Statement 2, defined in RFC 4130. Transfer runs over HTTP or HTTPS, secured with certificates. The recipient confirms receipt with an MDN.
What is an AS2 transfer, step by step
- Signwith own key
- Encryptwith partner certificate
- Sendvia HTTPS
- Verifysignature and content
- MDNreceipt
The signature proves who sent it. Encryption protects the content. The MDN proves receipt, also in legal terms.
The protocol is defined in standard RFC 4130.
What both partners need
- An identifier the AS2 ID, exchanged by both sides
- Certificates for signing and encryption, with an expiry date
- A reachable server with a fixed address that accepts messages around the clock
- A test with the partner before go-live
Expired certificates are the most common failure. An EDI service provider monitors expiry dates and renews in time.
What is AS2 compared to OFTP2 and SFTP?
| Protocol | Strength | Typical in |
|---|---|---|
AS2 | Signature, encryption, receipt | Retail, consumer goods |
OFTP2 | Large files, restart after failure | Automotive |
SFTP | Easy to set up | File exchange between systems |
AS4 | Web service based, successor | Peppol network |
BESITEC runs the connections for you. Your partners choose the protocol, you receive the data ready for your ERP.
AS2 FAQ
Do I need my own software?
Not necessarily. An EDI service provider runs the connection, your ERP only exchanges files with it.
What is an MDN?
Message Disposition Notification. The recipient’s signed receipt, sent synchronously right away or asynchronously later.
Is the protocol outdated?
No. It remains standard in retail. Peppol uses its successor AS4.
What does a connection cost?
It depends on the number of partners and the volume. We clarify it in a call and then quote a fixed price.
More terms in the glossary
A partner requires an EDI connection?
In 30 minutes, Vincent Rosenkranz, Sales & Marketing Manager, clarifies what your partner requires and how the connection works.
