What does a 503 error mean? Thaabit Mollagee March 09, 2016 08:47 Updated Follow This is a timeout error receive by merchants on 3D Secure when attempting to do a 3D Secure lookup. Related articles Wirecard API Response Codes What does error 9010 mean? What does error code “4030” mean? I receive an error “merchant not participating", what does this mean? Comments 0 comments Please sign in to leave a comment.