When couples sit down to plan their estates, they all face the same question:
Should you write one will together — or should you each write your own?
It feels like a simple choice. But the distinction between joint and mirror wills can have unintended consequences down the track — especially when it comes to revoking a will.
Here’s the breakdown:
Joint vs Mirror Wills is one of the most common questions among couples starting their estate planning journey. But many estate plans fail the surviving spouse down the track because they chose the wrong option. With Australians on track to inherit $3.5 trillion over the next two decades, now is the best time than ever to get this right.
For a full breakdown on what makes a will valid in Australia, visit https://www.cbm.org.au/stories/how-to-write-a-will-in-australia. When is revoking a will the right choice? Are there times when it’s not possible? Here’s what you need to know.
What You’ll Learn:
- What Is a Joint Will?
- What Is a Mirror Will?
- The Key Differences You Need to Know
- Revoking a Will: What Changes & What Doesn’t
- Which Option Makes Sense?
What Is a Joint Will?
Joint wills (aka mutual wills) are a single will document made between two people. They share the same executor, beneficiaries, and — most importantly — become binding on the survivor.
But here’s the kicker:
When one partner dies, their share of the estate automatically transfers to the surviving partner. This may sound great! But there’s a huge catch: the survivor is no longer allowed to change the will.
Living situations change. Relationships evolve. People mix blended families all the time. Without the ability to change beneficiaries, your estate plan could fail your family when it matters most.
That’s why joint wills are not recommended by most estate lawyers.
What Is a Mirror Will?
Mirror wills, in contrast, are two completely separate will documents.
Partner A creates a will. Partner B creates an identical will.
Example:
- Partner A leaves everything to Partner B (then kids)
- Partner B leaves everything to Partner A (then kids)
Partner A can make changes anytime.
Partner B can make changes anytime.
They mirror each other in content, but they’re legally independent documents.
The important distinction:
Mirror wills are not binding. Either party can revoke/update their will whenever they want — even after the other partner dies. They don’t have to tell the other person. Sometimes couples will include a written agreement to not make changes. But that’s the exception, not the rule.
The two can act independently at any time. With joint wills, the surviving partner is stuck with whatever terms are laid out, whether they make sense in the current situation or not.
The Key Differences You Need to Know
Both options have their pros and cons. But understanding how they differ is important before making any decisions.
Joint Will:
- One legal document for both partners
- Becomes irrevocable after partner dies
- No revoking a will after death
- Future updates are restricted & limited
Mirror Will:
- Separate legal document for each partner
- Either person can change their will anytime
- No notifying the other party when changes are made
- Most couples will opt for mirror wills
Mirror wills simply offer more flexibility. That’s why most estate advisors recommend them — particularly for young couples, blended families, or anyone who thinks their personal situation will change over time. Which again, is pretty much everyone.
Changing a will in Australia is simple and straightforward. Mirror wills just make that process easier for everyone involved later on.
Revoking a Will: What You Can and Can’t Change
If there is still any doubt about which option is better, it all comes down to revoking a will.
Both joint and mirror wills allow either party to revoke (cancel) their existing will anytime before they die. From there, the differences are night and day.
Once one partner dies, the surviving partner can no longer revoke the joint will. It’s permanently binding.
Imagine this situation:
A husband and wife enter into a joint will. They leave everything to one another, and then split their estate between their children.
The wife dies. Several years later, the husband remarries and now wants to update his estate plan to include his new wife.
With a joint will… he can’t. That surviving spouse and any children from the new relationship are not covered under the original estate plan.
With mirror wills? The husband simply revokes his existing will and creates a new one to include his new wife.
See how that flexibility helps?
What About Mutual Wills?
Mutual wills are worth mentioning before wrapping up. It’s a common term that gets confused with mirror wills quite frequently.
Mutual wills are not mirror wills.
Technically they’re two separate documents that come with a legally binding “contract” that neither party can make changes without consent from the other person. Upon death of the first party, both wills become irrevocable (just like a joint will).
Mutual wills work best if both parties want to ensure kids from previous marriages receive an inheritance — but beware. The courts have said there is a “heavy burden” proving mutual wills existed if there is no written agreement.
Which Option Makes Sense?
Mirror wills are hands down better for the majority of couples.
64% of Australians with minor children have no will at all. And when estates are contested, 51% of contested estates involve family provision claims. Having the wrong will (or no will at all) sets families up for exactly these types of disputes.
Joint wills may be convenient. But they can cause serious headaches for families later. Mirror wills provide flexibility as situations change.
The moral of the story?
If both partners are starting an estate plan from scratch, mirror wills are the right call. They provide a solid structure, easy updates, and complete freedom to revoke at any time.
Get professional legal advice and sit down together to create an estate plan.
It’s the best thing anyone can do for their future selves (and families).
Quick Summary: Joint Wills vs Mirror Wills
Joint and mirror wills let couples manage their estates jointly, but with different levels of flexibility.
Being able to revoke and edit a will is why most couples choose mirror wills. Joint wills are locked in when one partner dies, even if intentions change.
Here’s a quick rundown:
- Joint wills are a single binding document that cannot be revoked by the survivor
- Mirror wills are independent documents that can be edited or revoked at any time
- Mutual wills are two independent documents with an agreement neither party can make changes
- Revoking a will is as simple as creating a new will that replaces old terms (only possible with mirror wills)
The truth is — there’s nothing complicated about estate planning. Writing a will is the first step. Understanding the types of wills available makes the process that much easier.
