You don't need to fill anything in, just keep the warranty card/slips with your receipt.
Go to the Canon site & register online if you wish. You used to be able to ring them to register, but someone recently said you can't anymore? (not sure how true that is)
Definitely go online to www.canon.co.uk click on the 'support' tab and register your product. You'll need the serial number etc. if not registered you won't be covered.
Bruce, if you have a UK sourced Canon product that requires warranty repair your first port of call will be the retailer who sold it to you, it's up to them to sort the problem, weather it's registered with Canon on their website or not is in my opinion immaterial.
David
Well it's registered with CPS anyway![]()

It's actually Silver, Gold & Platinum
Only the basic level as only my 5D3 is considered higher than a Silver level body. I understand that the 7D wouldn't be classed as a Platinum level body but, considering it's their premium APS-C body, I'd have thought it'd have been classed as Gold at least.
Definitely go online to www.canon.co.uk click on the 'support' tab and register your product. You'll need the serial number etc. if not registered you won't be covered.