Hi Nigel, please check that the VAT due amount and the start and end period dates match those which were submitted to HMRC and then temporarily disable MTD in QuickBooks. To do this, click Edit VAT from the VAT dashboard > Edit settings > Toggle off the switch for MTD > Confirm on the pop-up (this won't impact any settings with HMRC). After this, click on Prepare return > Mark as filed. You can then switch MTD back on and the open return will reflect your next period due. :)