Insights

Why do population numbers change?

The Estimated Resident Population (ERP) is the official measure of population in Australia. It’s different to the Census count. The ABS publishes an updated ERP for states and territories quarterly, and annually for local areas, usually in March, for the period ending the previous June. These estimates are based on the last Census baseline, with adjustments for what’s known to have changed in the years since In 2027, there will be an additional update when the ERP is re-based to the 2026 Census data The ABS also updates the past 5 year’s ERPs with this release, meaning past measures of population since the last Census may also change. The 2021 Census (and the revisions) were distorted by the COVID-19 pandemic, resulting in significant revisions to population estimates for some states While we don’t expect the same magnitude of revision this Census, we won’t know until the numbers are out Local areas often don’t follow the wider trends. While your state or terriory may be growing, your local area may have a declining population