How Can I Prove Separation or Irretrievable Breakdown of Marriage?

31 July 2026

By bonfire

Proving separation or the irretrievable breakdown of a marriage can be more complex than many people expect. Understanding what the Family Court of Western Australia considers to be separation, including the evidence required and how separation under one roof is assessed, can help you prepare your divorce application correctly. In this guide, the team at O’Sullivan Davies explains how separation is proven and what information may need to be provided to the Court.

The Family Court of Western Australia does not consider the reasons for the marriage breakdown. Instead, the Court must be satisfied that the marriage has ended, that you and your spouse have been separated for at least 12 months, and that there is no reasonable likelihood of reconciliation.

Separation Under One Roof

Separation can occur even if you and your spouse continue living in the same home, this is known as separation under one roof. It may last for days, weeks, months, or longer. If any part of the required 12-month separation period was spent living under one roof, you must provide additional evidence to show that you were in fact separated.

This evidence will need to be filed in a separate Affidavit that needs to be signed under oath and accompany your divorce application. If insufficient information is provided, the Court may adjourn the application until further evidence is filed.

Proving Separation in Australia

The Court generally considers separation to have occurred when the parties stop living together in a marriage-like relationship. This may involve:

  • no longer sharing a bedroom
  • reduced or ceased emotional support
  • financial separation
  • changes to household duties or social activities
  • telling family or friends about the separation

In summary, to prove separation or an irretrievable breakdown of the marriage, you must show that you and your former spouse no longer live together in a domestic or marriage-like relationship and that this has continued for at least 12 months with no possibility of resuming the relationship.

Speak With an Experienced Divorce Lawyer

If you need guidance proving separation or have questions about the divorce process, the team at O’Sullivan Davies can help. Contact our experienced divorce lawyers today for practical advice and support tailored to your situation.