The confusion
People often use “joint will” and “mirror wills” interchangeably. They’re not the same thing — and choosing wrong can cause serious problems.
Mirror wills (what most couples want)
Mirror wills are two separate wills that reflect each other’s wishes.
How they work:
- Each person makes their own will
- Both wills have matching (or similar) provisions
- Typically: “Everything to my spouse, then to our children”
- Each will is independent
Key feature: Either person can change their will at any time, without the other’s consent.
Example:
Sarah’s will: “Everything to Tom. If Tom dies first, to our children equally.” Tom’s will: “Everything to Sarah. If Sarah dies first, to our children equally.”
Two documents. Same intentions. Complete flexibility.
Joint wills (rarely recommended)
A joint will is a single document signed by two people.
How they work:
- One document covers both people
- Often includes a “mutual will” agreement — a promise not to change it after one person dies
- The survivor is bound by the agreement
Key feature: The surviving person may be legally prevented from changing the will, even decades later.
⚠️ Warning: Joint wills can create serious problems. Most lawyers advise against them for good reason.
Why joint wills cause problems
Scenario: Tom and Sarah make a joint will leaving everything to each other, then to their children. Tom dies.
Sarah is now bound by the joint will. She cannot:
- Provide for a new partner if she remarries
- Adjust for changed circumstances
- Help a child who falls on hard times
- Respond to family changes (births, deaths, divorces)
She’s locked into decisions made years ago, when life was different.
When might a joint will make sense?
Very rarely. Possible situations:
- Blended families where both partners want to guarantee their children inherit
- High conflict situations where one partner fears the other will change everything
- Specific legal advice recommends it for your circumstances
Even then, there are usually better alternatives.
The better alternative for most couples
Mirror wills with a conversation.
- Make separate wills with matching provisions
- Discuss your intentions openly
- Understand either can change their will later
- Trust that you’ve chosen a partner who shares your values
If you’re worried your spouse will disinherit your children after you die, consider:
- A testamentary trust that protects certain assets
- Life insurance payable directly to children
- A binding financial agreement
- Having a deeper conversation about your concerns
🇦🇺 In Australia: Mutual will agreements (even in mirror wills) can be enforced, but the law varies by state. If you want to bind the survivor, get specific legal advice.
Quick comparison
| Feature | Mirror Wills | Joint Will |
|---|---|---|
| Number of documents | Two | One |
| Can change after spouse dies? | Yes | Usually no |
| Flexibility | High | Low |
| Common for couples? | Yes | Rare |
| Lawyer recommendation | Usually | Rarely |
What to do next
- If you’re a couple, you almost certainly want mirror wills
- Discuss your wishes with your partner
- Make two separate wills with aligned provisions
- If you specifically need restrictions, get legal advice about your options
Related: Why newly married couples need a will · Choosing the Right Type of Will