AS2 is a communication method that supports all Electronic Data Interchange (EDI) and any other exchange of information through the Internet using HTTP. Internet-based EDI communication has been available for some time, but its popularity increased in the early 2000s with the use of AS2 EDI and its products. In 2002, AS2 EDI was adopted as standard practice by the retail and CPG Industry, which increased the usage of AS2 EDI across various industries. 

AS2 differs from EDI because it uses TCP/IP — the primary communication language of the internet — rather than a Value Added Network (VAN), and the receiving machine must be connected to the internet when the message is sent. Like EDI, AS2 can handle all file formats and is ideally suited to the transferring orders and invoices. 

Part of AS2 EDIs popularity and efficiency lies in its use of digital signatures, receipts, data compression and encryption codes. All of these factors increase the security of EDI communication and information transmittance. Security is especially critical in an age where encrypted transactions are essential to avoid third-party unauthorised interception of company or client data. With AS2 EDI, companies can remain confident in transmitting sensitive business data.  

Every AS2 EDI document can receive an automatic response. With an AS2 system, the sending party is alerted when the document is received successfully, or if unsuccessful, a message informs them that the document will be queued for re-sending. This allows parties to know with immediate certainty that an EDI transactional set was sent without manually checking each time. 

AS2 is peer-to-peer, and as such, avoids using Value Added Networks, which can often have a charge associated with the traffic that passes through them.  

AS2 delivers greater security by creating an ‘envelope’ for EDI data, allowing it to be sent securely over the Internet – using digital certificates, signatures and encryption. 

Another benefit is that AS2 EDI doesn't depend on additional software at the supplier's end of the communication chain. Because AS2 EDI technology is "push” technology (Peer-to-Peer, also known as P2P), the speed of AS2 EDI communication is instantaneous because the document doesn't have to be stored and then forwarded. AS2 is unlike EDI communication using Value Added Networks (VAN), modems, or Bulletin Board Systems (BBS). 

An AS2 connection requires two locations to be configured to send and receive messages to and from each other — and if one of these locations is not available, the message could be missed. The technical competency required to set up and maintain an AS2 connection can be too great for many companies, with constant connectivity needed to ensure no messages are missed. Many companies, therefore choose to outsource their requirements to a specialist EDI provider who can ensure 24/7 connectivity. Outsourcing also means companies do not need to invest in dedicated hardware and software. 

An MDN (Message Disposition Notification) is an electronic return receipt which a trading partner can request during an AS2 interchange and is a method of acknowledgement that is sent to the sender to confirm the message has been transmitted completely. This is seen by many as an additional benefit of AS2 as it provides non-repudiation. 

AS2 is a standard connectivity method in the UK. Large retailers, including Tesco, Aldi, Lidl and Co-op, ask their suppliers to use EDI via AS2. 

If your business trades with these retailers, you may be asked to exchange AS2 EDI messages. 

However, EDI via AS2 is not limited to these businesses, and you may be asked to connect via AS2 EDI with any organisation. 

AS2 EDI is an internationally recognised and approved method for transmitting business documentation and data over the Internet in a secure manner. AS2 EDI is a simple way for global and international companies to communicate. This is especially true of those whose trading partners who already use EDI communication to transmit purchase order or inventory data. This method decreases costs and improves overall performance without restructuring the formats of EDI documents themselves. Many organisations have already transitioned to AS2 EDI communication