If you are receiving a 1046 error message after submitting your CT600,
to the HMRC gateway this is because the details entered
when attempting to file are incorrect, or they do not match
what HMRC are expecting. The EasyDigitalFiling Service sends your UTR together with User
ID and Password exactly as you have entered these.
To resolve this error message, please go through the steps below.
A UTR or Unique Taxpayer Reference is a number that is unique to you (the legal entity) Assigned by HMRC. This number is 10 Digits - Please ensure that you have entered it correctly with no spaces. You can validate that your UTR is correctly formed on this page What is a UTR Number
This may seem obvious however its very easy to enter numbers incorrectly
when reading from a form. Check that there are no transposed values and there are no spaces.
You can find more information on the HMRC website ( https://www.gov.uk/log-in-register-hmrc-online-services/problems-signing-in). Alternatively, contact HMRC directly to resolve this.Please note: If you contact HMRC, you should ensure that you have a Government Gateway account and not a gov.verify account, as the latter account type will not currently allow you to file online.
In order to file online, you have to associate your filing credentials with your UTR.
This is done by adding the Corporation Tax or Self Assessment service to your account.
After logging into your HMRC account as a new user, you will presented with a list of services. To register for coporation tax you will require your UTR and either your Companies House Registration Number (CRN) or your registered office postcode. You will then be sent an activation code by post. For individuals 'Self Assessment' should be the first item in the list, along with the UTR that you are trying to file against.
If the UTR is not displaying in either of the locations above, then you haven’t added the Self Assessment service to your account. You will need to do this before you can use these credentials to file online.
After selecting add service, you will need to wait for an activation code to be sent via post once received this code needs to be entered into HMRC's website. In some instances, you may need to wait 24 to 48 hours after activation before trying to file to HMRC. Please note that you have 3 attempts to enter the code otherwise you will be locked out and have to request another.
If you are filing for a partnership (SA800), the partnership will need its own set of filing credentials with the service added so that it displays that UTR rather than the UTR for the partner.