Forward sortation area and full postal code polygons, built from the block faces each code actually serves.
Why this differs from what you may have
Most postal boundary products are built by taking a representative point per postal code and growing a polygon from it. That works acceptably in suburban areas and fails in three places that matter: along arterials where opposite sides of the road belong to different codes, in dense downtown cores where a single building can hold several codes, and in rural areas where a code covers a route rather than an area.
This layer is built the other way round. Each address is attributed to a block face, each block face carries the postal code serving that side at that number range, and the polygon is the union of the areas those block faces serve.
Contents
- FSA polygons with address counts and dominant land use
- Full postal code polygons with address counts and delivery type
- A block face lookup table linking road segments to codes
Known limits
Rural route codes cover territory that is not meaningfully a polygon. They are supplied with a geometry_confidence flag set low, and should be used as a lookup rather than as a boundary.