Thu 10-Sun 13 November:
Toffee nut latte or frappuccino
Gingerbread latte or frappuccino
Fudge hot chocolate
Christmas blend filter coffee or latte
Chocolate fudge frappuccino
all 2-4-1 in any size. From 3-5PM for everyone. If you have Starbucks Rewards (free to join but must top-up) you can get until store closes (don't know how this works in 24 hour stores like Manchester Piccadilly and Trafford Centre Barton Dock Rd).
Excellent that Christmas blend filter is included which is £1 for tall in most stores, making it 50p per drink or 37.5p with your own cups.
Also can combine with AMEX spend £3 and get £1 back for another 1/3 off. Mastercard offer is on too I think £1 off when spend £5.