You may add new payment sources or change a source at any time in your LaTAP profile. After logging in and following the "My Profile" link to view your profile, you may view your payment sources at the bottom of the profile screen. To add a new payment source, click the "Add Source" link and enter the correct details. To change a source, click the desired source name from the list of payment sources to view the details for that source. The "Modify" button will allow you to change the details.