VAT return not submitted due to HMRC issue. Left it for 5/6 hours to try agaion but the report is no longer visable. Vat period 010626-300626 should be 010626 - 310826.

Update your VAT Filing Frequency in your settings from monthly to quarterly to correct your reporting period in QuickBooks Online UK. This change only applies to future periods and won't affect or file past ones.

Here's how:

1. Go to All Apps, then choose VAT.
2. On the VAT Overview page, select Edit Settings from the Edit VAT dropdown.
3. In the How often do you submit a VAT return to HMRC? dropdown, choose Quarterly.
4. Once done, click Save.

If a return was already marked as filed, changing your settings won't adjust that historical period. You'll need to contact an Intuit Expert, since they have dedicated tools to resync your Making Tax Digital information with HMRC.

This thread remains open if you have further concerns.