Further announcements relating to the abolition of HIPs indicate that you must 'commission' an EPC - but not receive it - before you market your property. However you must have an EPC within 28 days of marketing.
From 20th May 2010 Fridaysmove will provide EPCs free with Conveyancing - refundable upon completion. Any instruction for Conveyancing should count as a commission for an EPC.
Or you can purchase EPCs at £40 + VAT.