A joint will is a single will that's signed by two people, usually a married couple, leaving all their assets to each other. Seems simple and sensible—but it's almost always a bad idea. If you're an executor tasked with carrying out someone's wishes, the good news is that you're unlikely to have to deal with a joint will, because these days they're very seldom used.

What Is a Joint Will?

A joint will sets out the wishes of a couple in a single document that's signed by both parties. It's usually a will for a married couple, with or without children.

Typically, a joint will provides that:

• when one spouse dies, the survivor will inherit everything, and
• when the second spouse dies, everything will go to the children, if there are children.

A joint will appears to both fulfill many couples' wishes and address some of their key concerns. First, as many couples want, it provides that the survivor will inherit all the property of the first spouse to die. Second, it's then assured that no matter what happens after that, the children will eventually inherit everything. For example, if the survivor remarried, the children wouldn't have to worry that their inheritance would go to their new stepparent. Instead, because the terms of the joint will would be locked in, they would be guaranteed to inherit.

Compare the concept of a joint will to that of a "mirror will," in which each spouse creates a separate will but with reciprocal provisions—meaning they leave the same property to each other.

Can the Will Be Changed by a Surviving Spouse?

Most joint wills also contain a provision stating that neither spouse can change or revoke the will alone—which means that the will can't be changed after the first spouse dies. A conventional will is always revocable. But a joint will is really a binding legal contract, which cannot be revoked or changed after one spouse has died.

Mutual wills, or mirror wills, are sometimes irrevocable as well. Spouses might have come to a formal agreement not to revoke their separate mutual wills. And even if they haven't, sometimes courts will interpret the circumstances to mean that the couple meant for their joint wills never to be revoked.

Potential Problems With Irrevocable Joint Wills

Today, estate planning lawyers advise against joint wills, and they are now rarely used. Most lawyers will tell you that married couples need separate wills, or they will point you to different types of trusts. The reason is that making it impossible for the surviving spouse to change the terms of the will can turn out to be a very bad result. Moreover, joint wills can tie the surviving spouse's hands on even jointly owned property during the surviving spouse's lifetime.

In other words, the survivor—who may live years or decades after the first spouse's death—cannot react to changed life circumstances, and the family may suffer as a result. A joint will is typically very inflexible and may restrict you from many actions in ways you hadn't understood or anticipated.

For example, the survivor might not be able to:

• Give an adult child some of his inheritance early—perhaps to buy a house or start a business
• Help grandchildren with college expenses
• Put restrictions on money that will be inherited by a child who is financially irresponsible
• Sell the family home and buy something smaller, or move into an assisted living facility, or
• Sell or give away other assets covered by the will.

As a result, joint wills can lead to disputes and litigation that exhausts the time and resources of your loved ones.

There can also be estate tax complications if the estate is very large.

Some states (Wisconsin, for example), do not allow joint wills. If presented with a joint will, a probate court in these states will try to separate the document into two separate wills. If the document is written in a way that it can only become effective when the second spouse dies, the court will refuse to admit it to probate.

Is a Joint Will Ever a Good Idea?

If you have a simple estate, completely agree with your spouse about where you want your property to go after you die, neither of you get remarried, and your circumstances don't change, a joint will is probably not going to cause problems for you. However, few people can predict with certainty whether they will get remarried, or what major events will happen in their lifetimes, often decades after they create their wills.

Alternatives to a Joint Will

For simple circumstances, most couples can simply make separate wills that are revocable. Usually, these individual wills state that the will can be revoked at any time. This preserves flexibility for both spouses.

But if each spouse wants to bind the other spouse to certain obligations in the event that the spouse dies first, there are better approaches to take. For example, if you want to be sure that your children—and not some possible future second wife or husband of your spouse—will eventually inherit the family wealth, you can accomplish this goal without resorting to an inflexible joint will.

Most commonly, parents set up trusts for their children, attaching whatever restrictions they wish on the surviving spouse's use of the property, as well as who will manage the money, and how old the children must be to receive it. But other types of trusts are available as well. Generally, trusts are much more flexible and adaptable to specific situations.

Getting Legal Advice

If you're trying to create your estate plan and are considering a joint will, talk to an estate planning lawyer first. If your circumstances are not complicated, WillMaker can also help you make simple wills for a married couple.

If you're an executor and find yourself dealing with a joint will, talk to an experienced probate lawyer. These wills can raise many questions, and you'll need to proceed carefully.