It is free to look up postal codes using Canada 411 as of 2015. The website also allows searches of first and last name, street, city, province, and phone number at no cost.
The Canada 411 website is owned and operated by the Yellow Pages Group, a Canadian directory publisher. Searches are performed when information is filled into given fields. Complete searches yield precise results, so it is best to fill in all available fields when entering a search; however, if no results turn up for a search, then the entered information may be too specific. In this case, certain unnecessary words can be excised -- for example, directional indicators for a street name or a person's middle initial.
Reverse address and reverse phone number searches are also available on Canada 411, as well as a directions section.