Apparently, SIP currently only uses cardnumber to authenticate Koha patrons. I didn't write this patch, but it should check for userid when authenticating, if the cardnumber isn't found.
Created attachment 13538 [details] [review] Bug 9109 - Authenticate on userid as well as cardnumber
Hi David, I think this is a duplicate. *** This bug has been marked as a duplicate of bug 8039 ***