What is the difference between canonical and alias addresses?
The AddressFinder dataset consists of two sorts of addresses:
These addresses are the official addresses that are supplied to us by PSMA - the authoritative address provider for Australia. By default, the AddressFinder widget always selects the canonical addresses when performing autocomplete and verification operations.
Occasionally, an address can be referred to in a non-canonical (or incorrect) manner. Nearby suburb assignment is the most common reason, but there are other reasons such as commonly used mis-spellings, suburb or street renamings and ranged addresses.
AddressFinder allows a user to search for the address as they know it, and will often present alias addresses where appropriate. When the user then selects that alias address, our default action is to return the (corrected) canonical address.
The AddressFinder APIs will return a both an
id and a
canonical_address_id. API developers can choose to mimic the AddressFinder widget behaviour by using the
canonical_address_id field to query the Address Metadata API.
Sources of address aliases
An alias address is a sometimes used variation of the canonical address. The alias address is very similar to the canonical address but can differ in one of four ways. These are:
- The spelling/naming of street_name - in rare circumstances there may be more than one common variation in spelling of a street name. Each version of spelling will have its own alias address and these will be linked to the correct canonical_address.
street_namechanges - one alias address record will be created for the old street name during the transition period. This record will be linked to the correct canonical address.
street_numbervariations - these are a production of the AddressFinder service and alias the ranged street numbers of the canonical address for single street numbers within that range. This provides users with the ability to search and select both the ranged number or individual numbers from within that range. The single numbered address records will be linked to the ranged canonical address.
- Substitution of vanity/nearby suburbs - these are supplied by PSMA and substitute nearby suburbs into a series of address aliases. This provides users with the ability to search and select the ‘vanity’ suburb variations of their canonical address. The customer is happy as they can see and select their address (with vanity suburb) while you are able to collect the accurate (canonical) address data.