You will need to log into your online account and click on the payment tab. You will see a message saying you have pre-authorised with the organisation and to click the link to cancel. Once you have cancelled the link to the bank details you wish to change, the system will take a few minutes to action this for you. Then you can tick pre-authorise future payments again and confirm to be taken to the screen to put in the new bank details. Please be aware that cancelling your pre-authorisation will also cancel any payments made within the last 7 days.