I have started MTD part way through the year

Hi Richard145, thanks for joining the Community - to correct this, please temporarily disable MTD (from Taxes, select VAT > Edit VAT > Toggle off MTD) and then click prepare return > set the start and end period dates to the period prior to your current filing period > review the return > mark as filed. If you have several filed periods prior to this, you can mark each as filed individually, beginning with the earliest filing. 🙂