If you are on P11D then read this KB: https://www.iris.co.uk/support/knowledgebase/kb/p11d-failed-authentication-check-username-and-password/. If you get the Error Code 1046 in Business Tax – then run all the checks listed below.1.You must be … Continue reading Personal/Business/Trust Tax – Failed Authentication, check Client UTR, ID and Password (1046)