Not a discount code as such, but I have just signed up for Amazon Family on a 3 month free trial. Part of the deal is I get PRIME delivery (free, next day) for 3 months. Fantastic deal in the run up to Christmas (not to mention all the birthdays with my lot over the next 2 months).
They will charge me £50 after 3 months if I don't cancel before then. Diary is noted to cancel.