Withj only a few limited ocmpany clients we have been using the HMRC template for filing CT600 and accounts in iXBRL (pending trials of commercial software). The software is far from satisfactory but we've managed about half a dozen so far. Today's attempt has thrown up a new problem. After successful submission to Companies House, the submission to HMRC keeps failing. I get Error Code 1046 and the message "Authentication Failure. The supplied user credentials failed validation for the requested service".
I spent half an hour on the phone to the supposed Help Desk. After following instructions to amend certain security settings, the guy said it was because of a leading 0 in the company registration number (although this was the number inserted automatically when I downloaded the template). Eventually he logged the call to be passed to the Technical Dept. In the meantime I downloaded template (which interestingly showed a company number WITHOUT the leading 0) and created anew set of accounts and CT600 with otherwise identical info. Got exactly the same error!
Anyone got any suggestions at all?