diff --git a/src/main/java/network/oxalis/as4/inbound/As4InboundHandler.java b/src/main/java/network/oxalis/as4/inbound/As4InboundHandler.java
index efd956c..ad1e31c 100644
--- a/src/main/java/network/oxalis/as4/inbound/As4InboundHandler.java
+++ b/src/main/java/network/oxalis/as4/inbound/As4InboundHandler.java
@@ -83,6 +83,7 @@ public SOAPMessage handle(SOAPMessage request, MessageContext messageContext) th
         // Organize input data
         UserMessage userMessage = SOAPHeaderParser.getUserMessage(soapHeader);
 
+        validateUserMessage(userMessage);
         As4EnvelopeHeader envelopeHeader = parseAs4EnvelopeHeader(userMessage);
         messageContext.put(AS4MessageContextKey.ENVELOPE_HEADER, envelopeHeader);
 
@@ -166,6 +167,20 @@ public SOAPMessage handle(SOAPMessage request, MessageContext messageContext) th
         return response;
     }
 
+    private void validateUserMessage(UserMessage userMessage) throws OxalisAs4Exception {
+
+        boolean isNull = Stream.of(userMessage.getMessageInfo(),
+                userMessage.getCollaborationInfo(),
+                userMessage.getPartyInfo(),
+                userMessage.getMessageProperties(),
+                userMessage.getPayloadInfo()).
+                anyMatch(Objects::isNull);
+
+        if(isNull){
+            throw new OxalisAs4Exception("Error processing User Message. Incomplete Data.");
+        }
+    }
+
     private X509Certificate getSenderCertificate(SOAPHeader soapHeader) {
         try {
             return SOAPHeaderParser.getSenderCertificate(soapHeader);