You can view your completed transactions and use links for VAT receipts by going to Account, then Transactions.
You can click on any transaction to view more detail. When you view the transaction detail you also have the option to "Download Receipt" to download a VAT receipt direct to your phone in PDF format, or choose "Email Receipt" to have the VAT receipt emailed to your registered email address.
You can also have VAT receipts emailed to you automatically after each parking session if required. To do this go to Account > Notifications and check the box which says VAT sales receipts are available.