Quidco - £15 sign up bonus once you achieve £5 cashback
Quidco is a casback site similar to Topcashback, rakuten, etc.
You get rewarded cashback from a huge range of brands/websites, even sometimes bonus higher cashback % amounts! (Be sure to check all cashback sites when spending online to compare % if you're done with the bonus!)
There's over 4 thousand retailers to choose from to get cashback when spending through Quidco.
They're currently offering a bonus of £15 once you achieve £5 cashback by signing up through a referral link, this can be spread across multiple purchases.
You can cash out from as little as £1 via bank transfer and PayPal, as well as a huge range of giftcards for multiple major brands which have bonus % amounts for cashing out that way.
Non ref link - https://www.quidco.com/