Joint Wills for Couples: What you need to know about mirror wills and mutual wills

Joint wills are a way for couples with similar wishes to execute a will that benefits each other, should one partner pass away.

Joint wills are a way for couples with similar wishes to write a will that benefits each other, should one partner pass away.

So, a standard joint will might say…
  • When I die, my spouse, as sole beneficiary, inherits everything.
  • When the surviving spouse dies, our estate passes to our children.
You don’t even have to be a married couple, in a civil partnership, or in a long-term relationship. You can enter into a joint will with a sibling, friend, business partner, or anyone else you choose (and, most importantly, trust).

What types of joint wills are there?

There are two kinds of joint wills you’ll likely come across:
  • Mutual Wills
  • Mirror Wills
In essence, they’re identical: a document in which one party agrees to leave all their worldly possessions to the other in the event of a death, and the other party ‘mirrors’ these wishes. In the will, they also name beneficiaries who inherit after the surviving partner dies.


What’s the difference between mirror and mutual wills?

Mutual and mirror wills might be more or less the same, but there’s one clause that separates them:

Mutual wills cannot be altered after one partner passes away

Once signed, mutual wills become binding agreements, so if you remarry or have another child, you can’t include them in any new will.

Because of this, mirror wills are often the popular choice for both couples and solicitors, as they allow more flexibility and don’t tie the hands of either party.

That’s not to say mutual wills or mirror wills can’t be changed or even revoked, and you can still update your will, if necessary. However, both parties must be present and consent to any new changes. Any change to one will is then reflected in the other.

Are joint wills legal?

Joint wills, whether you choose a mutual or mirror will, are absolutely legal. In the eyes of the law, they’re considered two separate but similar documents.
But remember, for them to remain valid and legal, they must adhere to the principle that they’re created in tandem and can only be changed in tandem.

Do joint wills have to be identical?

Joint wills are generally identical to each other. That’s the nature of a joint will, and means, for example, if you and your partner share a house, they’ll inherit the property should you die before them, and vice-versa. When you throw variables into the mix, you’re removing what makes joint wills unique, but it is possible. For example, things like leaving additional gifts to people or charities, or choosing different executors of your will

Mirror wills: good or bad?

When deciding whether to opt for a mirror will, you and your partner will want to understand the risks and benefits.  

Advantages of mirror wills

Ease, speed, and reduced costs are three advantages, as your solicitor or will-writer won’t need to create two completely different documents. It’s essentially a cut-and-paste job, changing the names of the testators (who write the will)

Minimising inheritance tax is another advantage of mirror wills. According to the government, you won’t have to pay any inheritance tax if “the value of your estate is below the £325,000 threshold [or] you leave everything above the £325,000 threshold to your spouse, civil partner, a charity or a community amateur sports club.”
Since mirror wills see you make your partner sole beneficiary, you can manage any tax due and avoid unnecessarily paying Inheritance Tax.

Mirror wills can also be changed after one party has passed on. That’s a clear advantage for anyone whose circumstances change.

Disadvantages of mirror wills

Trust is a commonly cited problem with mirror wills.

Let’s say you and your partner agree to leave your house and money to your children. If you die, it’s technically possible for your partner to alter the will, disinheriting them and giving your family heirlooms to their new spouse.

You may also find the estate can be eaten up by care home fees, should either you or your partner need to be taken into care. So, even if you’ve agreed to give your children (or anyone else, for that matter) everything, they may not end up receiving the full dividends of your estate.

Mutual wills: pros and cons

Although they’re rarer, it’s worth understanding the advantages and disadvantages of mutual wills, so you and your partner can make an informed decision.

Advantages of mutual wills

A mutual will, like a mirror will, is a good way to share your estate between you and your partner. It’s a simple, cheaper option than signing individual wills, separate from each other. It’s all or nothing – but it’s up to you to decide whether that’s a good or bad thing.

Disadvantages of mutual wills

Inflexibility is a serious mark against mutual wills. For this reason, it’s unlikely that you’ll be offered one from a solicitor.

Ironically, that inflexibility can become wildly unpredictable – by taking one out, you’re assuming that your life, and those in it, are unchanging. This is especially true if you’re younger. What happens when you’ve only named your children as beneficiaries, but later have grandchildren and want to see them inherit some of your assets? Since a mutual will can’t be changed after one partner survives the other, it risks causing disputes between family members and potentially even becoming a contested will

Choosing the right joint will

With far more pros than cons – plus the ability to alter them as your life alters – mirror wills often tend to be the best option, though they’re not without issue. Discuss the different types of joint wills with your partner, then talk to a solicitor or professional will writer who can advise you on the best joint will for your current circumstances.

Want to make a mutual or mirror will?


We can put you in touch with up to 4 legal professionals to help you and your partner write a joint will

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Steve Clark

Steve creates helpful guides for The Law Superstore. He enjoys digging deep into new areas of the law, supporting partners, and translating legalese and jargon into plain English everyone can understand.

Want to make a mutual or mirror will?

We can put you in touch with up to 4 legal professionals to help you and your partner write a joint will

Get Quotes