In order to upgrade/downgrade your Traveling Mailbox account, please login to your account from a desktop or laptop at https://my.travelingmailbox.com. Upon logging in, please click the Billing tab on the left to enter the billing portal. Once in the billing portal, you can click the Subscriptions link on the left and then click the "Upgrade/Downgrade" button to reconfigure your plan.

Alternatively, you can login directly to your billing portal at https://travelingmailbox.com/my-account as well.