ABN Lookup is the public view of the Australian Business Register (ABR). It provides access to the publicly available information supplied by businesses when they register for an Australian Business Number (ABN). The most efficient way to search for a business is by ABN, ACN, ARBN, or ARSN. Searching by name will generally return multiple results ordered by relevance. The advanced search functions can be used to refine the results returned by a name search.
This service is available on the website, but can also be accessed programmatically using a SOAP API.