Lease Termination Notice and Delivery Method

[Geetika Casmon]

Hello, I am trying to deliver a notice for termination of lease without renewal option to 2 tenants (roommates). The lease ends on June 30, 2016. Within our lease terms, we are required to give 45 days notice. Is there any IL law which requires this period to be 60 days? Also, when giving notice, would you suggest certified mail to each of the tenants (although they reside at same location), requiring signature for receipt?