As a semi-regular on the BSL route, I can tell you that BA still offer duty-free on some intra european flights. They're often cheaper than HAL duty free, especially for cigarettes, but they don't stock much so sometimes you have to buy at the shop on the way out (and exit on the Swiss side, of course, otherwise it'd be illegal). I do wonder what the rules will be if/when (Brexit) happens and what form it takes. Getting 40 boxes/800 cigarettes from a tobacconist in SOF is a very good investment, especially if going on a TP run. Heck, with the cheap Saturday day-return fares for 40-50 quid, you could have a cheeky LCY-AMS trip, 10TPs, a leisurely lunch and stroll in Amsterdam, and you've made your money back on the first 10 packs so the next 30 are a bonus. So I'm not sure that having Duty Free reinstated between the UK and the continent would be that beneficial since we'd be limited in the quantities we can bring back!