If you are buying and second hand house in april, would you hv to pay house hold charge, it seems to me that its only for owner of property on 1st Jan 2012, below text from house hold charge . ie
Owners of residential property on the liability date of 1st of January 2012, subject to a limited number of exemptions and waivers set out below, are liable to pay the household charge by 31st of March.
+1 assuming it has been paid.
However you will be liable for whatever new version comes next year.