If you live in the London area TFL are collecting coats for the homeless
https://tfl.gov.uk/info-for/media/news-articles/let-s-help-wrap-up-london
– there are other drop off places, I spotted a notice at my local community centre this morning
http://www.handsonlondon.org.uk/wrap-uplondon/ should have more information
Also, if you have unwanted smart business clothes, smartworks have offices in London, Manchester, Reading, Edinburgh and Birmingham
http://smartworks.org.uk/
Smartworks is a women’s organisation,, there is a similar charity for men, Suited and Booted
http://www.suitedbootedcentre.org.uk/