Over 25% of the UK likely to have had Covid-19 already

Yeah this is just extrapolation and not based on actual tests. There is no way the number is as high as 25%.

I mean just look at New York or other hard hit areas, from the actual antibody tests performed the upper limit on the number of people who have had Covid19 is no where near 25%

I expect it's more around 5% and even that would feel high.