Identify whether the failure is in your software, authorisation, internet connection or HMRC’s service. Save dated evidence and use the appropriate support route. Complete the obligation as soon as possible; an error message alone does not guarantee a penalty appeal will succeed.
Identify where the problem sits
Check your connection and sign-in details, then the software provider's service information. Check HMRC's published service status through GOV.UK as well. HMRC's October 2026 agent update points users to its consolidated live service issues information.
If your accountant is filing, send the error wording and time of the problem. Avoid sharing passwords or security codes. The accountant should check the filing software and the relevant HMRC authorisation before repeatedly attempting the same submission.
Keep a useful incident record
Record when you first tried, the affected business and period, the error shown, relevant service notices and any support reference. Save screenshots that identify the issue without exposing unnecessary personal data.
For example, evidence that a particular service was unavailable when an otherwise complete submission was attempted is more helpful than a message saying only that the website was slow. Keep a note of when the service became available and what happened next.
Complete the outstanding obligation promptly
An outage does not mean the update has been received. Confirm the actual outcome after service resumes and keep the successful submission evidence. Do not send a duplicate purely because your progress screen is delayed.
Check the rules for the relevant year
HMRC does not apply late-quarterly-update penalty points for 2026/27, but the updates remain required. That treatment does not remove annual return or tax payment obligations. For other penalties, a reasonable-excuse claim depends on the facts and HMRC's rules; an outage is not an automatic guarantee of cancellation.
Contact your accountant early when an issue remains unresolved. TaxSimba can explain what information is needed for work within your engagement and help distinguish an outstanding filing from a display or access problem. Waiting until the last available minute leaves less time to investigate either.
Keep a useful failure record
Illustrative preparation example.
Record the attempted filing time, affected business, obligation, error message and support reference. Check whether authorisation, local connectivity or HMRC service status explains it. Keep the eventual successful submission separately; a support ticket alone does not prove the filing finished.
Check: Who owns the fault investigation and when will submission success be verified?
| Check | Practical action |
|---|---|
| Connection, access or service outage? | Check the relevant provider and HMRC status rather than guessing from a generic error. |
| What evidence shows the attempted submission? | Record time, period, exact error and support references without unnecessary sensitive data. |
| What happened after recovery? | Confirm the actual receipt status and complete any outstanding obligation promptly. |
Should I repeatedly resend until the dashboard changes?
First check the submission outcome. A delayed display is different from a failed filing and repeated attempts can confuse the trail.
Does an outage automatically cancel every penalty?
No. Relevant concessions and reasonable-excuse rules depend on the year and facts. Keep evidence and follow the notice's appeal process if needed.
Download a checklist for this guide
- Record the affected business, period and time.
- Save the exact error and relevant status notice.
- Check access and authorisation.
- Retain provider or HMRC support references.
- Confirm acceptance after recovery and save the acknowledgement.