The postal code is a six-character code defined and maintained by Canada Post Corporation for the purpose of sorting and delivering mail.

The form of the postal code is "ANA NAN", where A is an alphabetic character and N is a numeric character. The first character of a postal code represents a province or territory, or a major sector entirely within a province (Table 11).

Table 11. First Character of Postal Code and Corresponding Province, Territory or Region.

The first three characters of the postal code identify the forward sortation area (FSA). Individual FSAs are associated with a postal facility from which mail delivery originates. The average number of households served by an FSA is approximately 7,000, but the number can range from zero to more than 50,000 households. This wide range of households occurs because some FSAs contain only businesses (zero households) and some FSAs serve very large geographic areas. Rural FSAs are identified by the presence of a zero in the second position of the FSA code. As of May 2001, there were approximately 1,600 FSAs in Canada.

The last three characters of the postal code identify the local delivery unit (LDU). Each LDU is associated with one type of mail delivery (for example, letter carrier delivery, general delivery) and it represents one or more mail delivery points. The average number of households served by an LDU is approximately 15, but the number can range from zero to 7,000 households. This wide range of households occurs because some LDUs contain only businesses (zero households) and some LDUs serve large geographic areas. As of May 2001, there were more than 750,000 local delivery units.

Table 1 in the Introduction shows the number of postal codes and forward sortation areas provided by Canada Post Corporation that are valid as of May 2001 by province and territory.

The postal code is captured for all households from the address information provided by the respondent on the front page of the census questionnaire on May 15, 2001. The respondent's postal code is accepted whether or not it is the same as the postal code assigned by Canada Post Corporation to that address. The respondent's postal code is verified using the following criteria:

1. The postal code is valid as of May 2001.
2. The FSA of an urban postal code and the entire postal code for a rural area (FSA/LDU) is validated against a reference file at the census subdivision (CSD) level.

In cases where a postal code is not provided or where the postal code is not a current valid code, an imputation process assigns a valid postal code.

The postal code provided by respondents may not be the same as the postal code of the dwelling in which they live. For example, they may denote the postal code of their mailing address, such as a post office location (as in the case of general delivery) or a business location. Consequently, some respondents' postal codes may fall outside the FSA in which their dwelling is located.

Users should proceed with caution if postal codes are used as a proxy for standard geographic areas. Postal codes do not necessarily respect the boundaries of standard geographic areas (e.g., the same postal code can fall in two or more census subdivisions).

For more detailed information, refer to the Postal Code Counts User's Guide (Catalogue No. 92F0151GCE) or the Postal Code Conversion File Reference Guide (Catalogue No. 92F0153GIE). Note that these documents will be available in the Fall of 2002.