Abstract: Disclosed herein is a chemical dosing system for an appliance, such as a laundry washing machine or a dishwashing machine, having a water inlet, the system comprising a meter determining the volume of water supplied to the appliance, a pump for dispensing a quantity of a chemical to the appliance and a control unit arranged to receive a signal from the meter and to cause to be dispensed to the appliance a volume of chemical that is proportional to the quantity of water supplied to the appliance. The disclosed system may enable a correct quantity of chemical to be automatically dispensed to many types of appliance, without the need to know anything about the appliance, or to derive an electrical signal from the appliance.