Codicil to a Will: What It Changes, When to Use One, Key Risks, and When a New Will May Be Better

A will may remain unchanged for years, even when your family, assets, or wishes change. You do not always need to replace the entire document when only one part needs updating. 

Short answer: A codicil is a separate legal document that changes part of an existing will while leaving the rest in place. It can add, remove, or revise instructions. Because it affects a will, it generally must comply with the execution requirements of the governing law. 

Question	What to Know
Main purpose	Change specific instructions in an existing will.
Common uses	Replace an executor, alter a gift, or update a beneficiary.
Original will	Usually remains effective except where the amendment changes it.
Signing	Formal requirements depend on the governing jurisdiction.
Best suited for	Narrow, clear changes
When a new will may be better	When several provisions need rewriting
Main risk	Conflicting, unclear, or improperly executed documents

For more plain-English legal information, readers can also browse Knosten’s Law section. The site groups its general legal explainers there. 

What This Type of Will Amendment Actually Changes 

Think of the amendment as an additional legal document, not an edited page of the original will. It can amend or revoke part of a will without necessarily replacing the underlying document. 

Suppose your will leaves $10,000 to a relative, but you later want that gift to be $15,000. A properly prepared amendment can identify that provision and replace the original amount with the new one. The remaining instructions can stay unchanged. 

Other narrow updates may include: 

• appointing a different executor; 
• adding or removing a beneficiary; 
• changing a specific gift; 
• updating a guardian nomination where local law permits; or 
• revising a provision that no longer reflects your wishes. 

The wording should clearly identify what is changing without creating uncertainty about the rest of the estate plan. 

When a Codicil Makes Sense and When It Does Not 

This approach works best when the requested update is limited and easy to describe. For major changes, creating a new will may be clearer and easier to manage. 

A simple decision table can help: 

Situation	Focused Amendment	New Will
Replace one executor	Often suitable	Usually unnecessary
Change one specific gift.	Often suitable	May be unnecessary
Add one beneficiary	May be suitable	Consider the wider plan
Rewrite several gifts	Less attractive	Often clearer
Change the overall distribution plan.	Greater risk of confusion	Usually clearer
Several earlier amendments already exist.	Adds another document	Can simplify the record

There is no universal number of changes that automatically requires a new will. The practical question is whether someone could read all the documents later and understand your instructions without having to guess. 

How the Amendment and Original Will Work Together 

Codicil The original document does not disappear simply because you make a limited update. The executor may eventually need both documents to determine your final instructions. 

That can create a version-control issue that many simple definitions overlook. Imagine an original will followed by three separate amendments written years apart. Each may be valid on its own, yet the executor must still determine exactly how the documents interact. 

A clean rewrite can be easier when the paper trail becomes complicated. That does not mean every small change requires starting over. It means clarity matters as much as convenience. 

Legal procedures can also affect outcomes in other settings. Knosten’s guide to what a mistrial means offers another example of why the effect of a legal event depends on the rules behind it. 

Signing and Witnessing Rules Depend on Where You Live 

Do not assume that typing a change, signing it, and placing it beside your will automatically makes the update valid. Requirements vary by jurisdiction. Depending on where you live, an amendment may need to follow the same or similar signing and witnessing formalities as the original will. 

Local rules may address issues such as: 

• how many witnesses are required; 
• who may serve as a witness; 
• whether electronic execution is allowed; 
• whether notarization plays a role; 
• mental capacity at the time of signing; and 
• special rules for handwritten documents. 

This is why a form found online should never be treated as proof that your update complies with local law. 

What Can Make a Will Amendment Risky? 

The biggest problems usually arise from execution mistakes or unclear instructions. A document may create problems when it fails to meet local signing requirements, identifies the wrong clause, contradicts another provision, or leaves uncertainty about the person’s intentions. The risk increases when several documents modify one another. 

Storage can create another problem. An executor who finds the original will but not a later amendment may not have the complete set of instructions. 

Keep the documents together or store them in accordance with an appropriate estate-planning arrangement. Make sure the person responsible for your estate knows where the current records are kept. 

The broader lesson also applies before signing other legal documents. Knosten’s article on an early settlement offer after a car accident explains why understanding a document’s legal effect before signing it matters. 

Amendment or New Will: A Practical Decision Rule 

Start by listing every change you want to make. A focused amendment may be reasonable when you can describe the change in one or two precise instructions. A complete rewrite warrants closer consideration when the changes affect multiple beneficiaries, major assets, family circumstances, or the overall distribution plan. 

A new will can also reduce the risk of leaving executors with several documents that must be reconciled after your death. 

Professional advice may be especially useful when: 

• the estate contains substantial or unusual assets; 
• family relationships may lead to a dispute; 
• someone may question mental capacity or undue influence; 
• different states or countries are involved; or 
• I’m not sure how the proposed change affects another clause. 

Knosten also covers situations in which jurisdiction and legal status can affect the answer, such as when a gun rights lawyer may be needed. 

Your Next Step 

Codicil Read your current will from beginning to end and write down every provision you want to change. If the list is short, ask an estate-planning professional whether a focused amendment is permitted under your local law. If the changes affect the plan’s structure, ask whether replacing the will would create a clearer record. 

Keep the signed documents together or use another appropriate storage arrangement. Make sure your executor knows where the current estate-planning records can be found. 

Frequently Asked Questions