Being a single mum I’ve been using survey sites for almost 10 years now. And while they will never make me rich, the extra money here and there definitely comes in useful! My favourite one by miles at the moment is Prolific Academic . The surveys are quick and interesting, usually personality studies rather than the usual market research studies, and pay up to £2.50 or more per study. they also have a low cash-out threshold of £5 via Paypal, and the payment requests are usually processed within 5 days. A processing fee is taken from Paypal payments under £20. The only disadvantage I find is that emails alerting you of open studies are usually very few and far between, if you log into your account to check for surveys you will find them much more frequently.
I also like YouGov as they have never screened me out of a survey. It can get very annoying to waste 5-10 minutes answering questions just to be told you don’t fit the required demographic. Surveys usually pay 50-100 points each, the cash out threshold is high at £50 though so it does take a long time to reach, but is a nice amount to have when it does land in your bank! I have also won a £250 prize in one of their Oracle survey draws, so I can vouch for the fact that real people do indeed win.
Another good one is Crowdology , they have a low payment limit of £4 by Paypal and the payments come through almost immediately.
Power of Opnions have very short (2-3 minute) surveys, the minimum payout is £10 but they take a small fee for Paypal payments, you can get around this by ordering vouchers from places like Marks and Spencer and Amazon.
There are many other reputable survey sites that I use, alongside GPT (Get-Paid_To) and mystery shopping sites. Expect a blog covering some of these in the near future!