Can a Notice of Objection be amended after it's already been filed with an Ontario court?

A Notice of Objection can generally be amended after filing, for example to add a further ground for objecting to the will, correct an error, or update the objector's information as the matter develops. Ontario courts generally take a flexible approach to procedural documents like this, especially early in a dispute, because the goal is to have the real issues between the parties properly identified rather than have a case decided on a technicality in the original paperwork.

That flexibility isn't unlimited. If an amendment would introduce a substantially new and different ground for objecting, particularly late in the process or after significant steps have already been taken, the estate trustee or another party can oppose it, and the court will weigh factors like prejudice to the other side, delay, and whether the new ground could have been raised earlier. In some cases the court may allow the amendment on terms, such as requiring the amending party to cover costs the amendment causes. Because getting the grounds right the first time avoids this back-and-forth, it's worth taking care — and getting legal advice — before the original Notice of Objection is filed, rather than relying on being able to fix it later.