Various errors can occur during the processing of an enterprise service. Some errors, such as input of inconsistent data, can be resolved by the end user of the application consuming the service. Errors that cannot be solved by an end user, such as non-availability of technical resources or implementation bugs in the consumer or provider application, are indicated using a ‘fault message type’ message. Each namespace contains a fault message type StandardMessageFault that is used by the operations of SAP service interfaces.

In the case of synchronous services, fault messages are returned to the consumer. When implementing the consumer application, they are typically reflected as exceptions thrown by the consumer proxy class. In the case of asynchronous services, the fault message is not returned to the consumer but is instead retained by the local SAP NetWeaver Process Integration (SAP NetWeaver PI) engine for monitoring.