I need to get QB to calculate VAT at the point of the invoice being paid rather than at the invoice date?

Hello there, @matt-baron. Let me share a few insights about how to calculate VAT when the invoice is being paid.

QuickBooks has two accounting methods. These are: 

• Standard. Choose this if you track and pay VAT as of the invoice date.
• Cash. This is ideal for you since you want to pay for it later after your customers pay you.

You can select a method as to how you track and pay your VAT. Follow these steps below to set this up on the VAT page: 

1. Go to the Taxes menu on the left menu. 
2. Choose Edit settings in the Edit VAT drop-down list. 
3. Select the button for Cash under the VAT accounting scheme.
4. Click Save when done.

For more information, you can also read through our help article: VAT: Getting Started. It also contains links to different VAT topics. 

I'd be delighted to know how it goes, @matt-baron. We're always here if you need further assistance. Have a nice day.