If you already have a Now TV Box then Asda currently has 20% Off Now TV, Sports Pass 1 Week usually £10 now £8.00 , 3 Months entertainment pass or 2 month movies pass usually £15 now £12 @ Asda until 8th Jan.
If you don't have a box then I believe Tesco direct are about the cheapest at the moment at £14.24,for the 3 months entertainment or 2 months movies.
No codes, no cashback claims ( that eventually fail ), no wild goose chases hoping for a Glitch, no manipulating new customer discounts, just an old fashioned instant discount at the checkouts. Buy the pass instore at Asda and use.
These Passes can be found on the Gift Card Stand which I believe are on the back of checkouts in most stores.