What side hustles are classed as taxable?

I've been using various different ways to increase my income on a monthly basis and want to double check what does and doesn't need declaring. This is what I've been doing: - completing surveys through Prolific - Selling old clothes/other bits on Vinted/Ebay - Current account switch incentives - Completing paid projects like data collection through Appen/TestingTime - Bank referral schemes (e.g. refer a friend, spend X amount and both get £20) Any insight would be super helpful, thanks

Hi
Please look at this information Register as a sole trader