This Charity is close to my heart and i know they are always looking for used stamps to help to raise funds
SANDS
Just cut/ tear round the stamp and send them to the address
that follows when you have a few. SANDS are the Stillbirth and
Neonatal Death Society - they provide support for family and friends
affected by the death of a baby, at or soon after birth. They also
support research into looking at ways to prevent avoidable baby
deaths.
The address for SANDS stamps is:
Stamps for SANDS, c/o JetStamps, Hartwood Road, Southport,
Merseyside, PR9 9AN