Hello and welcome to the Community, Philip
HMRC requires that the MTD connection is re-authorised periodically every 18 months. If you don't see a prompt on your VAT dashboard with steps to re-connect, please instead disconnect and reconnect MTD in QuickBooks. To do this, access your MTD settings:
1. Select the gear icon, and then Account and settings.
2. Select Advanced.
3. Next to Making Tax Digital, select the pencil icon.
Disconnect from MTD:
1. In Advanced, select Making Tax Digital to expand the section.
2. Select Learn how to disconnect.
3. Select Continue.
4. Select Disconnect to confirm.
5. Select Continue to return to QuickBooks Online.
Re-authorise MTD:
1. Go to Taxes and select Set up MTD.
2. Select Authorise now.
3. Select Continue.
4. In the window that opens, sign in with your MTD Government Gateway user ID and password.
5. Select Continue.
6. Select Give permission.
If you need any further help, please get back in touch below!