WITCHPLZ
Just seen it on Facebook, haven't tried it yet but hopefully it will work on sale items. Stack with 7% cashback @ shopback.
Enter code WITCHPLZ at checkout to receive discount. Ends 19:00 AEDT on 30 October 2019. Code can be used multiple times per customer up to a maximum pre-discount spend of $950 per order. Can’t be used with other promo codes or on gift vouchers, delivery charges, Premier Delivery or ASOS Marketplace. Country exclusions apply. Selected marked products excluded from promo.
Make sure to check the UK store, as it's usually cheaper