Global Estate Planning: International Wills in New South Wales

With the increase of access to international travel comes the increase in accumulation of assets outside of the jurisdiction in which a person lives. This has led to increasing need for estate planning instruments that can be relied on in alternate or multiple legal jurisdictions.

One means of addressing this need is the concept of the “international will.” This is a single testamentary document which is in a format capable of being recognised in multiple jurisdictions so that it can deal with assets in each of those jurisdictions.

Each sovereign nation has its own history and has had its own laws develop in different ways over different time frames. This has led to entail where a fixed portion of the estate is to the children or spouse, Sharia law where the Muslim religion has an influence on who the beneficiaries are and what they are to receive and countries, like Australia, where there is testamentary freedom but obligations as to how the wishes are recorded.

The International Will: A Uniform Approach?

The United Nations (UN) have long been working on facilitating private and commercial law between different jurisdictions. As part of this work they held the Convention Providing a Uniform Law on the Form of an International Will, in Washington, D.C.. This convention which concluded on 26 October 1973 seeks to simplify the formalities required for a will to be recognised as valid across jurisdictions. It establishes a uniform standard for the form of wills intended to operate internationally.

The Convention does not govern the substantive validity of wills, e.g. forced heirship, but focuses instead on formal validity — ensuring that a will executed in accordance with the Convention’s requirements will be recognised as valid in other jurisdictions, regardless of the testator’s nationality or the location of assets.

Australia's Accession and the NSW Implementation

Australia does not automatically incorporate treaties directly into its legislation. It took time for each state and territory to agree and legislation to be prepared to enact the treaty. New South Wales enacted the Succession Amendment (International Wills) Act 2012 (NSW). This gave effect to the Convention and allowed testators in New South Wales to execute wills in the international form.

The international will regime in NSW coexists with the existing provisions of the Succession Act 2006 (NSW), offering an optional and alternative mechanism for those with international interests. A will executed in the prescribed international form will be formally valid in NSW and other jurisdictions who have confirmed the treaty into domestic laws.

Key Features of an International Will

Under the Convention and the NSW legislation, an international will must meet the following requirements:

• It must be in writing (handwritten or typed).

• It must be signed by the testator in the presence of two witnesses and an authorised person (a legal professional or notary empowered to supervise the execution).

• All parties must sign in each other’s presence.

• The authorised person must complete an Annex Certificate (attesting to compliance with formalities), which is appended to the will.

  
  

The will need not be drawn in any particular language, nor is it required to comply with any additional formalities imposed by local law (e.g. publication, registration, or sealing). It is the certificate and compliance with the Convention’s prescribed form that secure its formal validity internationally.

Practical Advantages and Limitations

An international will can be a valuable instrument in multi-jurisdictional estate planning. It offers certainty and predictability for testators with foreign-held assets, dual citizenship, or family members in other countries. However, it is important to note:

• The Convention only binds contracting states. As of 2025, relatively few countries have adopted the Convention. These including Australia, Belgium, parts Canada (Alberta, British Columbia, Manitoba, Ontario), France, and Italy. Notably, jurisdictions such as the United States and United Kingdom are not parties to the Convention. Countries such as Russian Federation and Iran have signed the Convention but have not confirmed it within their domestic legislation.[1]

• The Convention deals solely with formal validity. The succession law will still be determined by conflict-of-law rules in each jurisdiction, and local laws may override testamentary intentions on substantive grounds.

  
  

Implications for Estate Planning in NSW

Legal practitioners in New South Wales advising clients with international connections should consider whether an international will is appropriate, especially where:

• The client has property in another country that is a party to the Convention.

• The client seeks a single will to cover all assets, minimising administrative complexity.

• There is a need to ensure consistent formal validity across multiple legal systems.

  
  

However, due diligence is essential. Clients must be made aware of the Convention’s limitations and the potential for conflict with foreign succession regimes. The international will is not a one-size-fits-all solution but a useful addition to the estate planner’s toolkit when deployed strategically.

In many cases, it remains appropriate to consider separate wills in each relevant jurisdiction, particularly where the laws differ significantly or where assets are held in civil law jurisdictions with strict formal or substantive rules.

For legal assistance and advice tailored to your personal circumstances please contact our team.

This article is not legal advice, and the views and comments are of a general nature only. This article is not to be relied upon in substitution for detailed legal advice.

[1] , https://www.unidroit.org/instruments/international-will/status/> Unidriot website accessed 22/08/2025.

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