Hello, my grandma is thinking to be absent from Canada for more than six months so she needs to stop the OAS. Would a phone call to service canada be enough? or do they need a letter from her? what other info do they need as well. thank you for your help.
a phone call to service canada would at least answer your question.
If she is anywhere near a physical location of a Service Canada outlet--they have several across the country--she can just drop in and fill out a form they have on the spot.
Why does she not just arrange to have her OAS electronically transferred into her bank account? Then she can access it from abroad , or just leave it in the bank account for when she gets home in six months.
Service Canada prefers electronic deposits: cheaper and faster.