Bank of Montreal clients had services restored Thursday morning after an overnight outage, the bank says.

"Our services have returned online although some customers may experience delays in transactions being processed and posted," reads a post from BMO on X, formerly Twitter.

"Customers can access banking services through their local BMO branch … or via our BMO ATM network. We thank you for your patience and apologize for any inconvenience."

In a statement to CTV News, the BMO said the service disruption was caused by a "false fire alarm" pulled at one of the bank's data centres Wednesday night.

Third-party monitoring site Downdetector showed spikes in user reports for outages, jumping from a baseline of at or near zero during the daytime Wednesday to nearly 200 in the 10 p.m. hour, dipping overnight and rising again until 7 a.m, then decreasing in the hours since.

Issues appear to have affected both Canadian and U.S. clients.  


This is a breaking news story. Check back for more information.

With files from's Joshua Freeman and Courtney Heels