What's the best ukulele capo under £10?

For keeping the spend down, I'd start with the Flight Aluminium Ukulele Capo Silver. Its listed best new price is £6, making it the cheaper of these two ukulele-specific options.

The Mahalo Ukulele Capo also fits your budget at £9. There's no supplied detail on clamping pressure, padding or neck compatibility, so paying more isn't evidence of a better fit.

Before buying either, check compatibility with your ukulele's neck. A good capo should hold the strings cleanly without pulling them noticeably sharp; fit matters more than the small saving.