American Moving to Canada. Do I Need Apostilles? What Documents?

[hearthandhardcovers]

Hello,

I had unfortunately never heard of the term "apostille" until today and now am scrambling to figure out if I need my documents internationally notarized. I will be applying for a CUSMA Work Permit mid-September at the border but now wonder if I will have enough time.

Moreover, will I need this if I am applying for a Spousal Sponsorship? Thank you!