Was just browsing the Calumet website to buy some more film, and I see they have a 10% off discount code for film before the end of March, just by using the voucher code DEVELOPING. Their prices are actually incredibly good anyway, and if you spend £50 or more it's free next day delivery too, which is ace.
I've just bought a box of 120 Ektar 100, a box of 120 Portra 400, a box of 120 Tri-X and 3 rolls of 120 FP4+ (so 18 rolls) for £66.60 delivered. Can't complain about that especially when the same would have cost £98.77 from Silverprint or £91.17 from AG.
Plus, if you use Topcashback you get 5.25% back on top of that too