I'm in a 12 month contract with an ISP which does not support FTTP (only FTTC), and expect Openreach to implement the fibre connections (following a voucher-funded CFP) before the expiry of the "old" ISP contract. How long a grace period is there before I am obliged to start a new full FTTP service contract? I've heard 28 days AND 3 months (from Openreach) and 12 months from word of mouth. Can anyone shed light on this in reality please?