A reverse look-up for postal addresses in Ontario is available on the Canada Post website. Canada Post is the primary mail delivery service in Ontario.
Postal codes are unique to each area in Canada. Entering a postal code on the reverse look-up feature on the Canada Post website generates a number of addresses for each postal code. This feature narrows down the area in which a person lives. It is difficult to determine the exact address of a person using his postal code only. This feature may be helpful to companies wishing to determine the areas in which their customers are located.