revised 5th January 2012 by Alison Ford

1046 filing error: Authentication Failure

An error code 1046 is a verification error which is produced by the Government Gateway and is caused by one of the errors below:

1. The UTR (for SA100/SA800/SA900 returns), Tax Reference (Corporation Tax) or PAYE Reference (P11D or Payroll) is incorrect for the client.
2. The Gateway credentials you have used to try and submit the return are incorrect. Note: You need to enter uppercase and lowercase letters exactly as they were sent to you by Government Gateway.  To rule out this error, try logging into the Gateway using your credentials, if you are successful re-apply them to the submission.

What if my error is not caused by any of the above?

You should contact HMRC's online services helpdesk - see http://www.hmrc.gov.uk/efiling/efiling_helpdesk.htm for contact details.  HMRC Online Services will recommend that you contact your software provider if you receive an internet filing error whilst using 3rd party software.  This makes sense for the majority of filing errors.  Most errors relate to the values submitted on the return so can be tested and diagnosed by our developers.  1046 errors are different as the investigation is reliant on client specific information that HMRC will not release due to client confidentiality.  For cases where HMRC are unable to provide an answer please contact support with the full error message, background of the case and a Case Reference Number from HMRC.  The Software Developers Support team at HMRC will assist us with your enquiry.