Applicability Statement 4 is an open standard for the secure and payload-independent exchange of business-to-business documents using web services. Secure document exchange is governed by aspects of web services security, including XML encryption and digital XML signatures. Payload agnosticism means that the document type (e.g., purchase order, invoice, etc.) is not bound to a defined SOAP action or operation.
This is a conformance profile of the OASIS ebMS 3.0 specification.
AS4 became an OASIS standard in 2013 and an ISO standard in 2020. Most AS4 profiling points that constrain the ebMS 3.0 specification are based on the functional requirements of the AS2 specification. By miniaturizing ebMS 3.0 using AS2 as a blueprint, AS4 provides an entry ramp for web services in the B2B sector by simplifying the complexity of web services.