The "HMRC Login Failed" error means HMRC didn't accept the Government Gateway credentials you entered when submitting your CT600 (User ID, password, or UTR). It's not related to multi-factor authentication - the HMRC filing gateway uses a separate authentication method that isn't affected by 2FA on your Government Gateway account.
Could you double-check:
1. Your Government Gateway User ID is correct (12 characters, for your organisation account not personal)
2. The password is correct - try logging into Government Gateway directly at gov.uk to confirm
3. Your Company UTR (Unique Taxpayer Reference) is correct and linked to that Gateway account
If your Gateway login works on HMRC's site directly, try submitting again with the same credentials. If it still fails, let us know and we can look into the specific error on our side.
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Could you double-check:
1. Your Government Gateway User ID is correct (12 characters, for your organisation account not personal)
2. The password is correct - try logging into Government Gateway directly at gov.uk to confirm
3. Your Company UTR (Unique Taxpayer Reference) is correct and linked to that Gateway account
If your Gateway login works on HMRC's site directly, try submitting again with the same credentials. If it still fails, let us know and we can look into the specific error on our side.