Interac says its e-transfer and Interac Online services are up and running again following an outage on Monday evening.
The debit card service says a technical issue "knocked the network out for about five hours."
Numerous users awaiting e-transfers took to social media to complain about the outage and the lengthy wait for transfers to work.
Interac issued a tweet to customers at about 11 p.m. ET saying notifications were being sent but that it would "take some time" to work through the backlog.
The company said it expected the backlog to "clear over the next few hours" and notifications would be sent automatically or manually.
Interac, which also apologized to its customers, has not yet indicated what caused the outage.