Yes, you do have to provide authentication information for your bank. It's done through a third party service called "Plaid" ( no relation to the Tesla Model S Plaid ). My financial advisory firm uses this Plaid service to gain access to my financial assets in external platforms, and it's never been a problem for me. If you're not comfortable using the Plaid service, you should be able to bring a certified bank check with you when you pick up the vehicle. Of course, you should confirm this with Tesla.