Understanding Provisional Mortality Data for Jan - Mar 2025

Each death registration in the national mortality dataset has 3 dates:

• The date on which the death occurred.
• The date on which the death was registered with the jurisdictional Registry of Births Deaths and Marriages (RBDM).
• The date on which the death was lodged with the ABS.

When looking to measure change over time, the completeness of data for the most recent period is important. When data is received each month by the ABS, the lag between the date of death and the date of registration means that approximately 40-50% of reported registrations are of deaths that occurred in the month being reported. The remainder are deaths that occurred in earlier months.

In June 2025, the ABS received 16,541 death registrations. Of these, 16,310 deaths occurred in 2025, 185 occurred in 2024 and the remaining 46 occurred in 2023 or earlier years.

For deaths which are doctor certified, approximately 95% of registrations are received after a second month of reporting, while for coroner certified deaths, the proportion of registrations reported after a second month is lower (approximately 80%). This is because it takes longer for coroners to certify deaths due to the complexity of investigations.

As coroner referred deaths make up a smaller proportion of all deaths (approximately 11-14%) their inclusion in all-cause data only reduces the overall completeness by around 2%. This should be considered when making comparisons with historical counts, noting also that the level of completeness will be higher for the start of any given month than the end of that month.

This pattern of registration and reporting is highlighted in the table below, which also shows the slight variation in reporting timelines by cause of death.

According to the source: Australian Bureau of Statistics.