Originally Posted by
CPH-Flyer
I don't think I ever checked in at a London hotel without being asked for ID.
The UK does not have a national i.d. system (or the requirement to carry i.d. with you). Therefore if your account address is located in the UK, you are not legally obliged to provide i.d. and many hotels won't ask. A willingness to pay the bill with a credit card in the name of the reservation holder is more than enough.
If your address is international, you are more likely to be asked for i.d.