Is there a way to get QB to automatically include VAT from a previous quarter that has not already been included?

Welcome to the Community forum, @dee79. 

I recognize how relevant it is to include VAT automatically from a previous quarter. Currently, this option is unavailable in QuickBooks Online.

Rest assured our product engineers are continuously working to roll out enhancements based on our customer's requests. 

In the meantime, you can edit the previous quarter and manually include the VAT. This way, it will be visible when on your account.

I'm also adding these articles for your reference in the future :

• VAT: Getting Started
• Set up and edit VAT settings, codes, and rates

Fill me in if you have other questions about managing VAT in QuickBooks. I'll be happy to help you again. Stay safe!