There is currently only one plastic milk bottle top recycling scheme in the UK that we are aware of. This scheme is run by GHS Recycling based in Portsmouth. They collect bottle tops from charities and community organisations throughout the South East of England. Please call GHS on 02392 670399 to find out if there is a collector near you.
Rest of England - bottle tops have very little monetary value; 6p per kilo or 40 - 60p per black bin bag (approx 7 to 10kg) or £60 a tonne.
It is not economically viable for you to collect bottle tops for charity unless you are living in the South East of England.
If you want to raise funds for charity here are some tips;
Pay a visit to your local scrap yard and find out more about recycling scrap metal