You can easily update your payee details in the mobile app by going to Pay > Manage Payees. From here you can add a new payee, edit or delete an existing payee.
To add a payee click on the plus button bottom of screen and follow the prompts.
To update a payee click on the existing payee name, then edit and update details as prompted. Confirm by clicking update.
To delete a payee slide the payee summary card from right to left, click on the bin icon and then confirm to delete.