Some consumers were unable to use ATMs or call 911 emergency services due to the disruptions, which started on Friday morning.
One of Canada's biggest telecommunications firms, Rogers, reported on Saturday morning that "the great majority" of its customers had their services back.
There is no estimated date for complete repair. Another tweet from the business stated that it will "proactively reimburse all clients," and it claimed to have "every technological resource
Rogers addressed "the impact our outage is having on your life" in a letter posted on its website in the late afternoon.
Just before 9AM ET, Rogers tweeted the first response to the outage from its official support account before going dark for a few hours.
The business tweeted on Friday afternoon that it was making efforts in restoring services "with our worldwide technology partners."
Local media reported that a major telecom giant's network breakdown on Friday caused issues with cell services and internet access for Canadians.
Rogers recognised "the impact our outage is having on your life" in a late-afternoon post on its website, adding that it had "every technical resource at our disposal."
We will let you know as soon as we are aware of the precise moment when the Networks will be fully functional. We are concentrating on the solution right now.