H1A 0A1, H1A 5B6 and H1C 1J8 are a few examples of Montreal postal codes. Like all Canadian postal codes, metropolitan Montreal postal codes have a six-character alphanumeric code separated into two three-character segments. As of July 2015, all postal codes in Montreal start with the letter H.
The first three characters of a Montreal postal code determine the Forward Sortation Area. This designates a geographical region, so many postal codes begin with the same three characters. The last three characters determine the Local Delivery Unit. This code designates a particular building, city block or small town. According to Zip-Codes.com, Montreal has 400 postal codes.