What Is the Biggest Mistake with Wills?

Most people think having a will means their estate is handled. It’s not that simple. The biggest mistake with wills is treating them as a one-time task rather than a living document — and that single error can trigger a chain of costly, painful consequences for the people you love most. Whether it’s a will that hasn’t been updated in a decade, a missing guardianship clause, or poor planning around probate, the details matter far more than most people realize.

At Oak Road Wealth Management in Lee’s Summit, MO, we work with families that need legacy planning. This article breaks down the most common — and most damaging — will mistakes, so you can avoid them.

Executive Summary

The biggest mistake with wills is failing to keep them current and complete. Outdated wills, missing guardianship designations for minor children, vague asset distribution language, and failure to plan around probate are the leading causes of estate disputes, family conflict, and unnecessary financial loss. A will is not a “set it and forget it” document — it requires regular review and strategic planning alongside beneficiary designations and estate planning tools like trusts.

What Happens If Your Will Is Outdated?

An outdated will is often worse than no will at all, because it creates a false sense of security.

Life changes constantly — and your will needs to keep pace. A divorce, a new child, a remarriage, the death of a named beneficiary, or a significant change in assets can render your existing will dangerously out of alignment with your actual wishes.

A client names their ex-spouse as the primary beneficiary before a divorce is finalized, or a new child is born and never added to the document. Without an update, those oversights become legal realities. Wills must be reviewed and revised with every major life change — marriage, divorce, the birth of a child, the death of a named heir, or a significant shift in financial circumstances. This isn’t optional maintenance; it’s essential planning.

Major life events that should trigger a will review include:

• Marriage or remarriage
• Divorce or legal separation
• Birth or adoption of a child or grandchild
• Death of a named beneficiary or executor
• Significant change in assets or debts
• Moving to a different state (inheritance laws vary)

Does a Will Avoid Probate?

No — and this surprises many people.

A will does not avoid probate. In fact, a will must go through the probate process to be legally validated and enforced. Probate is the court-supervised process of authenticating a will, paying debts, and distributing assets to heirs.

Probate can be a genuine nightmare. Depending on the complexity of the estate and the state where you live, probate can take anywhere from several months to several years. Court costs, attorney fees, and administrative expenses can consume a significant portion of the estate — sometimes 3% to 7% or more of the total value. And your family may have a difficult time accessing the funds during this process.

The solution is not to skip writing a will — it’s to pair your will with proper estate planning strategies. Revocable living trusts, payable-on-death (POD) accounts, and correctly titled joint assets can pass directly to beneficiaries outside of probate, preserving time and money for the people you leave behind.

What Is the Biggest Mistake People Make with Wills?

The single biggest mistake is treating a will as a standalone document rather than one piece of a comprehensive estate plan.

A will alone cannot control assets that pass by beneficiary designation — such as life insurance policies, 401(k)s, IRAs, and joint bank accounts. Those assets transfer automatically to whoever is named on the account, regardless of what your will says. If those designations are outdated, your will cannot override them.

Common mistakes that compound this core error:

• Failing to name or update beneficiaries on retirement accounts and life insurance
• Relying solely on a will when a trust would be more appropriate
• Using vague language that creates ambiguity
• Naming a minor child as a direct beneficiary without a custodian or trust in place
• Not naming an alternate executor or successor trustee
• Storing the will in a location no one else knows about

Why Is a Guardianship Clause So Important for Minor Children?

If you have minor children and your will does not name a guardian, a court will decide who raises them.

A guardianship clause designates who will care for your children if both parents are deceased or incapacitated. Without one, the court appoints a guardian based on their own assessment — which may not align with your values, your relationships, or your children’s best interests.

Not including a guardianship clause doesn’t just create legal uncertainty — it can create genuine hardship for your kids during the worst moment of their lives. Family disputes over who should raise the children are common when no guardian is named. Those disputes are painful, expensive, and entirely avoidable. If you have minor children, naming a guardian is not optional — it is one of the most important decisions your will makes.

When naming a guardian, also consider:

• Naming an alternate guardian in case your first choice is unable to serve
• Separating the financial guardian (who manages assets) from the personal guardian (who raises the child) if appropriate
• Having a direct, honest conversation with the named guardian before finalizing the document

How Often Should You Update Your Will?

At minimum, review your will every three to five years — and immediately following any major life event.

Estate planning attorneys and financial planners generally agree that wills should not sit untouched for decades. Tax laws change, family dynamics shift, and financial situations evolve. A will written in your 30s may be entirely inadequate in your 50s.

FAQ

What is the most common mistake in a will?

The most common mistake is failing to update a will after major life changes such as marriage, divorce, the birth of a child, or the death of a named beneficiary. A will that doesn’t reflect your current circumstances can distribute your assets in ways you never intended.

Does having a will mean you avoid probate?

No. A will must go through probate — the court-supervised process of validating the document and distributing assets. To avoid or minimize probate, you need additional planning tools such as a revocable living trust, payable-on-death account designations, or jointly titled assets.

What happens if I don’t name a guardian for my minor children in my will?

If you do not name a guardian, a court will make that decision for you. This process can be contested by multiple family members, is emotionally difficult, and may result in an outcome that does not reflect your wishes. Naming a guardian — and an alternate — is essential for any parent with minor children.

Can a will override a beneficiary designation on a life insurance policy or retirement account?

No. Beneficiary designations on life insurance policies, IRAs, 401(k)s, and similar accounts override what is written in your will. These accounts pass directly to the named beneficiary, regardless of your will’s instructions. Keeping beneficiary designations up to date is just as important as updating your will itself.

How often should I update my will?

Review your will every three to five years as a general rule, and immediately after any major life event — marriage, divorce, birth of a child, death of a beneficiary, significant change in assets, or relocation to a different state.

Is a will enough, or do I also need a trust?

For many families, a will alone is not enough. A trust can help avoid probate, provide more control over how and when assets are distributed (especially to minor children), and offer privacy that a will — which becomes a public record through probate — does not. An estate attorney can help you determine which tools are right for your situation.

Oak Road Wealth Management is a financial planning firm serving Lee’s Summit, MO and the surrounding area. This article is for informational purposes only and does not constitute legal or tax advice. Please consult with a qualified estate planning attorney for guidance specific to your situation.

Written by Andrew Matz, Financial Planner at Oak Road Wealth Management.