The good news: Your Accounts were successfully filed to Companies House on 21 January 2026 and accepted.
The issue: Your CT600 submission to HMRC failed because HMRC didn't accept your Government Gateway credentials. This is a login/authentication issue, not a problem with your tax return data.
How to fix this:
1. Go to your dashboard and click on SERAPHIX LTD
2. Click "Update Credentials & Retry" (or select "View CT600 Error" from the dropdown)
3. Double-check your Government Gateway User ID - this is usually 12 characters
4. Verify your password is for your business Government Gateway account (not your personal one)
5. Confirm the Company UTR matches what HMRC has on record
Common causes:
- Mixing up personal vs business Government Gateway accounts
- Typo in User ID or password
- Not yet enrolled for Corporation Tax online with HMRC
If you haven't filed a CT600 online before, you may need to
https://www.gov.uk/guidance/enrol-your-company-for-corporation-tax-online with HMRC first. This is a one-time setup.
Once your credentials are correct, you can retry the submission and it should go through. Your form data is saved, so you won't need to re-enter anything.
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The issue: Your CT600 submission to HMRC failed because HMRC didn't accept your Government Gateway credentials. This is a login/authentication issue, not a problem with your tax return data.
How to fix this:
1. Go to your dashboard and click on SERAPHIX LTD
2. Click "Update Credentials & Retry" (or select "View CT600 Error" from the dropdown)
3. Double-check your Government Gateway User ID - this is usually 12 characters
4. Verify your password is for your business Government Gateway account (not your personal one)
5. Confirm the Company UTR matches what HMRC has on record
Common causes:
- Mixing up personal vs business Government Gateway accounts
- Typo in User ID or password
- Not yet enrolled for Corporation Tax online with HMRC
If you haven't filed a CT600 online before, you may need to
https://www.gov.uk/guidance/enrol-your-company-for-corporation-tax-online with HMRC first. This is a one-time setup.
Once your credentials are correct, you can retry the submission and it should go through. Your form data is saved, so you won't need to re-enter anything.