Our bank is moving to a policy to remove inactive online banking customers after 90 days of inactivity. I think we should give the customers a change in terms notice as required by Reg. E 205.8 (a) and Reg. DD 230.5(a)(since our TIS Disclosures in the Additional Terms section states Free Online Banking and Free unlimited online bill pay). What is your opinion/advice?

I would look at your original contract for guidance. If you are silent on the issue of cancelling the service, you might want to consult legal counsel on the proper notification practice.