It’s after photos emerged of bags of clothing lined up on the street outside Cancer Research UK in New Malden High Street.
Kingston Council says leaving items outside is classed as fly tipping, is illegal and costs the authority time and resources to remove them.
Markings will be drawn on the pavement outside charity shops to see if they deter people from dumping their donations.
For ore information, click here kingston.gov.uk/fly_tipping