We currently allow you to link only one bank at a time to any given Stockpile account. If you want to change your linked bank, send a quick email to firstname.lastname@example.org that says "Cancel my bank link so I can set up a new one" or something along those lines. Please be sure to send the email from the email address you use as your Stockpile ID, so we know it's coming from you.
Why are we being so restrictive? It's because money launderers and other bad guys love moving money in from one account and out to another. It's a favorite trick in their playbook, and as a U.S. financial institution, we have to guard against it.
Still, we don't want to make it hard for you, so we're working on a new way to give you a way to link multiple bank accounts without letting the bad guys in. We'll let you know when it's ready!