CoolCalmT Welcome to FT

When you transfer the points from SPG/UR to an airline ffp, you then try to get an award flight using that airlines frequent flyer miles. You can use 1 airline's ff miles with another airline (ff partners). Award availability is always an issue. Note that FF miles are not equal.

For ffp's look here http://www.flyertalk.com/forum/infor...help-here.html Generally you are better to join a USA or Canadian airlines ffp.

This thread http://www.flyertalk.com/forum/trave...demptions.html links to http://www.economicalexcursionists.com/travelTools/ (but no all ffps are listed). Plug in YVR LHR and also YRV LGW. Also SEA is a viable option. That tells you how many ff miles are needed. So about 25,000 ~ 30,000 miles/avios/points one way.

UK has a tax (APD) when leaving. Some airlines, like BA, have high cash surcharges on awards.