Hello there, @BigTee, 

I appreciate you setting the default VAT code in the Chart of Accounts page to help reflect the VAT amounts on the expenses. 

I'll help ensure you're able to amend transactions in bulk so the VAT figures will be calculated. 

The second paragraph provided by my peer above refers to updating the VAT code for future transactions, not the previous ones. This maybe the reason you're unable to see the VAT for them. 

If you have an accountant that uses QuickBooks, I'd suggest checking with him/her since they have the ability to reclassify the transactions for past and future transactions. Please see the screenshot below about reclassifying the transactions. 

In case there's no accountant to consult with, I'd suggest deleting all credit card transactions and re-import them. For more information, here's a great article you can refer to: Add and Match Downloaded Banking Transactions.  

The options above will help you achieve your goal, @BigTee. 

I'm here anytime you have other online banking concerns. Have an awesome day!