When a user is transitioned to OAuth authentication, they are still able to connect multiple accounts from one financial institution. For example, they can connect a personal account, a business account and a spouses account all from the same institution, in their online banking experience. 

To add an additional account with the same institution, the user will navigate to "Add an Account" > select the financial institution > select that they want to add another account> and will be redirected to the financial institutions website to enter the other accounts login credentials