I am thinking of trying these guys:GreenIBIS Recycling as they are based in Worthing which is only up the road from us. I have around 100 toner cartridges from HP Laserjet printers, collected over the last couple of years, couldn't bear to just throw them out. The only problem is that they say the cartridges must be put into boxes for collection with around 20 in each! Some of these cartridges are huge so we don't have boxes big enough to fit 10 in , let alone 20!
They don't charge anything to pick them up though and they seem happy enough if the cartridges are refurbed ones, not genuine HP.
Will re-post when we've had them collected.