What Is a Codicil?

If you already have a Will and just need to make a small update, you may not need to start from scratch. A codicil is a legal document that allows you to change, add to, or revoke parts of your existing Will—without writing an entirely new one.

Codicils can be a practical way to keep your Will up to date as your life evolves. But like all legal tools, they must be used correctly to remain valid and effective.

Learn what a codicil does and how it works with your existing Will

A codicil is a written amendment to a previously signed Will. It refers back to the original document and details specific changes—without replacing the entire Will.

Common uses include:

Changing your executor or guardian
Adding or removing a beneficiary
Updating a specific bequest (e.g., gifting a different item)
Correcting an error or outdated detail

Codicils are legally binding when signed and witnessed properly, following the same formalities as a full Will.

Tip: A codicil should clearly reference the original Will by date and include only the new or revised instructions. This helps avoid confusion about which version governs your estate.

When a Codicil Makes Sense—and When It Doesn’t

Codicils work best for straightforward changes. But if you’re making multiple edits, restructuring your estate, or reacting to major life events, it may be cleaner to draft a new Will.

Here’s how to decide:

Use a Codicil If...	Consider a New Will If...
You need to change a name or swap an executor	You’re changing several parts of your Will
You’re adding one gift or removing one beneficiary	You’ve experienced a major life event (e.g., marriage, divorce)
Your estate is otherwise unchanged	Your asset mix or family structure has significantly evolved
You want a quick update that’s easy to verify	You need to eliminate ambiguity and start fresh

Too many codicils can make your intentions unclear, especially if they contradict each other or are hard to follow during probate.

The Legal Requirements to Make a Codicil Valid

Just like your Will, a codicil must meet specific criteria to be legally enforceable. This includes:

Being written and signed voluntarily
Signed in the presence of two qualified witnesses (in most provinces)
Dated and clearly linked to your original Will
Stored safely with your original Will, not separately or loosely

Important: Never write on or mark up your existing Will. Handwritten notes or cross-outs can invalidate your Will entirely. If you need to make a change, use a proper codicil or draft a new Will.

Using Codicils Wisely in Your Estate Plan

Codicils are tools—useful when applied with care. But they’re not always the best answer. If your Will starts to look like a patchwork of updates, that’s usually a sign it’s time to consolidate with a new document.