Flying out of LHR to CPH Sunday morning at .0700 with BA. Anyone have any idea as to when duty free opens?

T-5 or T-3? Duty Free shops will be open if there are flights going out -- I've seen them open as early as 5AM, but I'm sure the LHR website has all the information . . .

Terminal 5

Found it

Check if you can whether it is actually worth buying duty-free rather than duty paid elsewhere. Often you can find things cheaper or as cheap in normal shops.

Definitely true. While liquor is cheaper at duty free than elsewhere in the UK, it often is more expensive than what you can find at home. You can save on high end cosmetics but not a huge amount. I tend to use Duty Free just to use up and left over £ currency for last minute gifts or sweets/biscuits/munchies. I have bought leathers -- one wallet and one Radley handbag which seemed to be cheaper than the high street.

I understand but we are going to Scandinavia where I suspect it’s much more expensive although I have not visited the region for a few decades.

Some drinks are more expensive in Scandinavia eg Pimms or some whiskies, gin etc but on the whole prices are similar esp for wine,

Some duty free is worth buying @ LHR, I bought a litre of Tanqueray from T3 for £10 which was on offer.

Bombay gin 14 pounds
smirnoff vodka 10 pounds
and a few others on special

Exactly, there are some good offers ATM.