Understanding HMRC and Companies House error codes
Authentication Errors
Errors like '1046: Authentication Failure' mean the credentials you provided were rejected by the gateway. This is almost always due to a typo, an expired password, or entering the wrong credential type (e.g., entering a Gateway ID where an Auth Code is expected).
Duplicate Submissions (Error 3300)
If you see an error indicating a duplicate submission, the government system already has a completed record for this exact accounting period. You cannot overwrite it. If you need to fix a mistake, you must file a formal amendment.
Date Mismatches
Errors regarding accounting periods usually mean the start and end dates you entered in WeFile do not perfectly match the dates Companies House or HMRC have on file. Log directly into the respective portals to verify your official dates.
UTR and CRN Conflicts
If the gateway reports that the UTR does not belong to the company, double-check your records. This often happens if you manage multiple companies and accidentally mix up their 10-digit UTRs.
Validation Schema Errors
Occasionally, you may see a complex XML schema error. This usually indicates that a piece of data you entered (like a very long address line or an invalid character) violates the strict rules of the government's receiving system. Review your recent text inputs.
System Downtime
Errors mentioning 'Gateway Timeout' or 'Service Unavailable' mean the government's servers are currently offline for maintenance or experiencing an outage. In these cases, your only option is to wait a few hours and try submitting again.