The following instructions do not apply to subscriptions to Tugboat Premium. For those subscriptions, please contact your Tugboat account executive or Tugboat Support.
From here, you can:
Go to username -> My Projects at the upper-right of the Tugboat dashboard.
Select the project where you want to change the billing info.
Go to Project Settings.
Scroll down to Your Plan.
Click the Billing Information link.
From here, you can: