Is it permissible to use JSON format in implementing SOAP web services?

SOAP (Simple Object Access Protocol) is a message exchange protocol that traditionally uses XML for message formatting. The JSON format is not used in the standard implementation of SOAP, as the SOAP specification is based on XML.

However, in modern integrations, RESTful services with JSON are sometimes used, while SOAP services typically use XML. If JSON needs to be used, it is usually not SOAP anymore, but another type of web service (for example, REST API). Therefore, the use of JSON in the implementation of a classic SOAP web service is not permitted.