I've a few bras that were bad buys in terms of sizing and are almost new.
In the past I've sent bras like this to a charity which either sold them for cash or sent them overseas for women.
I also know that M&S used to offer a £5 voucher for a bra you gave them and I think it was then donated.
In the past I also took some to my local Oxfam shop but they don't seem to have any on display now (and it was too busy inside to queue and ask!)
Any updates?