First time posting on this site .... so here goes ......
I used to live near the Watford U.K. store before moving here to the U.S. This site has also easy access from the M1 Motorway (exit Junction # 5) that leads north from London. I used to have a U.K. membership account however, that has now expired. I now have a U.S. account and used it on my last visit to a U.K. store (Manchester, NW England) and found that it did not 'swipe' at checkout, the operator had to manual input my membership # before it was accepted.
Hope this of some help.