The Freecycle Network, Westminster group
It's a grassroots and nonprofit movement of people who are giving (and getting) stuff for free in their own towns and neighborhoods: https://groups.freecycle.org/group/WestminsterUK/posts/all
Bulky Waste Collection by Westminster City Council
Items that are too big for your standard rubbish bag or bin, as well as all electrical items, need specialist handling.
https://cleanstreets.westminster.gov.uk/services/bulky-waste-collections/
Nextdoor
Local community social network
Reconnect Network
London’s independent volunteer scheme providing free services to the homeless.