Thank you for the screenshot. It looks a bit different on my screen (see below) but I think I went to the right place 
Thanks for this advice. I think my buyer account has been separated from my seller account from the beginning. I have 2 different logins; one for each side. I also always use separate browsers; Chrome for seller account and Edge for buyer account. Does this mean that my buyer and seller are separated? Is there other way to check?
The bank account on the buyer side I think is intended for purchases as direct debit, but I’m pretty sure it would work for adding and show up on your seller account since everything seems to sync there. I really don’t think it’s necessary though as we have had no issues changing it in SC in the past.
-Ana
Ok … you have two separate accounts … one you use to buy and one you use to sell … with different login emails. In this case, the bank on the account you buy on would not transfer accross to the seller account. You actually have 3 accounts … 1) the buyer account with it’s own email login … 2) the seller account with it’s own login … and 3) there is a buyer account attached to your seller account that is under the seller login email.
How to get to the buyer account associated with the seller account.
Login into your seller account.
Open a tab and in the browser bar type in amazon.com
This will open to the buy side of Amazon and will be logged in the same as your seller account.
Now got to settings > account info > payments.
In the wallet, you should see the credit card and bank account that you use with your seller account.
This is where you would update the credit card and/or bank account that you want associated with your seller account. Wait 24 hours and then add the updated credit card and/or bank account (deposit account) to the seller side.
DO NOT put your business credit card and/or bank (deposit) account on the buyer account that has it’s own login. This should be your personal use credit card and/or bank account.
Thank you so much for the steps and clear explanation! 
I just copied and pasted these steps into my SOP for changing bank deposit account. So I know how to do it next time (if the rules don’t change) 
