What is the difference between a waiver and a notice of fulfillment?
A waiver removes a condition you could have relied on. A notice of fulfillment confirms it was satisfied. Both make the deal firmer, and which one you sign can matter if a problem surfaces later.
A waiver says you are giving up the protection regardless of whether it was met. A notice of fulfillment says the condition was actually satisfied, for example that financing was approved.
Why the distinction can matter: if a problem later turns out to relate to the subject of the condition, your position differs depending on whether you waived the protection or confirmed it was met. Your lawyer will tell you which is appropriate.
What matters more in practice is the deadline. Conditions do not quietly lapse in your favour. Depending on how the clause is drafted, missing the date can end the agreement or bind you to it, and either outcome is one you did not choose. Put every condition deadline in a calendar with a two day warning the moment the offer is accepted, and get the document delivered in writing before the time on the page.
Next questions
What conditions should I put in my offer?
Financing and inspection at minimum, plus status certificate review on a condo. Each is a dated right to walk away with your deposit, and each one you remove makes your offer stronger and your position worse.
Ontario
Can I back out of an accepted offer?
Only through a condition, before its deadline. Otherwise you are in breach: the seller keeps your deposit and can sue for their loss on resale, which Ontario courts have awarded well beyond the deposit amount.
Ontario