I'd thought about the month's notice of charges changes before. However, it depends on how the MOD defines it. Does the change need to be notified a month before 1 Apr when you start "owing" it, or is it a month prior to the last working day of Apr when you actually pay it?
Guess which one my money is on? Do any lawyers, professional or amateur, know? As a landlord, I understand that I have to tell my tenants a month before they start "owing" the money rather than rent payment day.