Beta Deltas API

  • Version: 0.6.0
  • Host:
  • Protocols: https
  • Accepts: application/json
  • Responds With: application/json

What is the deltas API?

The Deltas API is a RESTful API designed to respond to server incremental updates of spatial data (the Delta) in response to queries primarily dimensioned around time.

Why the Deltas API is important to you.

For businesses that traditionally consume our quarterly data supply, this will be a dramatic change allowing you to update your existing data store easily by requesting the change between two points in time allowing you to maintain a continuously updated dataset of Australian address information.

For businesses that want to be able to leverage an understanding of change across Australia, be those new developments, subdivisions or name changes. You will be able to query for that change, giving you an advantage in your industry while saving time and money.

API limitations

This data and the API are in beta, meaning you should expect bugs and possible odd behaviour. Below is a list of known limitations when using this API.

  • When an address that didn’t have a G-NAF ID is assigned a G-NAF ID when a new release of G-NAF is published we do not flag that as an action update.

Data limitations

Just like the API, the data is evolving. Below is a list of known limitations.

  • ACT, WA, SA, data is missing primary addresses when there are multiple subaddresses.
  • Deltas go back to the 1st of August 2018 with WA as an exception, their data only goes back to the 25th of January 2019

Data Coverage

As we improve our process the deltas API will have more and more data coverage. The information below is a transparent look at the current state of data coverage found in the deltas API. G-NAF Coverage is the number of records we currently match to an existing G-NAF record, Good coverage would be greater than 95% of records have a relationship to an existing G-NAF record. Complete Addresses is a very simple measure of the percentage of records that have, street number, name, locality, state and post-code. Valid Geometry is a measure of the number of records that have a geometry (geolocation).

Deltas are now loaded daily


  1. G-NAF coverage: 89.73%, Complete Addresses: 95.14%, Valid Geometry: 99.05%

By State/Territory

  1. ACT: total: 226,066, G-NAF coverage: 88.23%, complete addresses: 100.0%, valid geometry: 100.0%
  2. NSW: total: 4,284,468, G-NAF coverage: 95.31%, complete addresses: 95.74%, valid geometry: 99.41%
  3. NT: total: 105,970, G-NAF coverage: 89.39%, complete addresses: 97.85%, valid geometry: 99.9%
  4. QLD: total: 2,741,206, G-NAF coverage: 98.59%, complete addresses: 100.0%, valid geometry: 100.0%
  5. SA: total: 1,127,630, G-NAF coverage: 97.27%, complete addresses: 99.45%, valid geometry: 99.99%
  6. TAS: total: 857,848, G-NAF coverage: 90.15%, complete addresses: 99.99%, valid geometry: 100.0%
  7. VIC: total: 4,067,593, G-NAF coverage: 88.19%, complete addresses: 90.29%, valid geometry: 100.0%
  8. WA: total: 1,355,072, G-NAF coverage: 97.51%, complete addresses: 99.69%, valid geometry: 100.0%

Frequency of data

Each jurisdiction has a different release schedule, PSMA is working closely with these jurisdictions to increase the rate of supply to daily. Currently, the frequency is as follows:

  • Daily = ACT, NSW, WA and QLD
  • Weekly = SA, TAS and VIC
  • Monthly = NONE
  • Quarterly = NT (moving to daily)

Key concepts you should know before you start developing

  • Attributes are pieces of information about a specific resource. An example would be the geospatial coordinates of an address or what local government area that address belongs to.
  • Resources are the representation of a thing or an object that can have some data attached to it (attribute). Examples are a specific address, a building or a parcel of land. We will often have unique identifiers for these things.
  • Methods are the operation that is being performed on a resource. Examples are get, update and delete
  • Collections are sets of logically grouped resources. Examples are addresses, properties, suburbs and hospitals
  • URL or (Uniform Resource Locator) is the path to the resource.

Remembering these key concepts will help you to navigate our APIs quickly and efficiently.

We need feedback

The initial release of the deltas API will focus on address information with the aim of adding more themes of data in the future based on customer feedback.

This is our initial understanding based on market feedback, but we need more input to ensure we’re building the right service for your business. Please reach out to us on with all of your feedback, the good the bad and the ugly.