Free UK money - best cashback deals early 2020

Here are some great UK cashback deals, valid in early 2020.

£40 cashfor switching to So Energy. Cheap energy, 100% renewable, easy switching guarantee and a great website. Use this link to claim your cashback money
£10 cashfor a new Amex card, 5% cashback for the first 3 months (limit £100 and 1% cashback on all purchases (card is free, works with Apple Pay) - click this link to claim cashback money
£5 cashfor a new Curve card, sign up here (app for a phone) and use promo code EKGZYQQN for the cash. It's a Mastercard that links all your existing cards, and currently gives 1% cashback.
£40 cashfor a new Zeux account, using promo code BBSJ2Y. Download the Zeux app from your appstore, select "Get free Zeux credit" then select "Enter a referral code" and enter BBSJ2Y.
£20 Amazon voucherfor taking out a Spectator subscription for 12 issues for £12, so effectively £8 free, use this link and remember to cancel before auto renewal

(I've been surprised how widely accepted Amex is now: Tesco, Sainsbury's, ASDA, Morrisons, Amazon, etc. Only B&Q and Cambridge City Parking meters haven't accepted it).