From the Lott website:
To delete a Debit or Credit Card you will need to login to your online account.
Once logged in, click on the account icon in the top-right corner and select Funds from the drop-down menu.
Under the 'Add funds to my online balance' section you will see the Debit and Credit Cards registered to your account.
Click on the delete button below the details of the card you wish to remove.
A pop up window will appear where you need to click Yes to delete the card.
The card should no longer appear in the 'Add funds to my online balance' section of your account.
From the Lott App:
Below we are using a Tatts account as an example.
Once logged in, click on the account icon at the bottom of your screen.
Select Manage Credit Cards from the menu.
Select the Debit or Credit Card that you wish to remove and choose Delete Card from the options.
A pop up notification will appear where you need to click Proceed to delete the card.
The card should no longer appear in your account.