On October 1, 2026, Microsoft will begin disabling Exchange Web Services (EWS) by default across Microsoft 365 and Exchange Online, with a permanent shutdown scheduled for April 1, 2027. Unlike other technology deadlines that announce themselves, there will be no crash or pop-up alerts. Instead, software that condo corporations rely upon every day will quietly stop performing certain functions.
The window to flag applications that still require EWS and keep them running past October 1, closes at the end of August 2026. Understanding what is changing—and preparing ahead of the deadline—will help avoid unexpected disruptions.
What is changing and why it matters
EWS is the connection layer that most third-party software has historically used to integrate with Microsoft’s email and calendar infrastructure. Organizations that use on-premises Exchange Server will not be affected.
For condo corporations, the practical consequence is not a Microsoft problem — it is a third-party software problem. Any application that was built to connect to Outlook through EWS and has not been updated to use Microsoft’s modern replacement will lose that connection. The software itself continues to function. The integration does not.
The failure mode is the problem
When EWS is disabled, everything will seem to work until someone requires a necessary function that is no longer accessible.
Consider the applications common to Ontario residential condominium management: amenity booking platforms, visitor management systems, work order and maintenance tools, email archiving solutions, shuttle scheduling software. Many were built years ago, when EWS was the industry standard. Some have been updated. Some are in progress. Some have not started, and some particularly older custom-built platforms where the original developer no longer exists, will never be updated.
Any application that hasn’t migrated to the new connection standard will produce no error message. Amenity bookings will stop syncing to calendars. Visitor logs will stop updating. Email archives will stop capturing communications. Work order notifications will stop delivering.
The first indication will appear as a need that is suddenly missing: a status certificate required on a tight deadline, a maintenance record needed for an insurance claim, or board communication that becomes critical in a legal dispute.
At that point, the discovery that the archive has a months-long gap is not a technology conversation. It is a governance conversation.
Why boards are exposed
Under Ontario’s Condominium Act and its regulations, corporations have obligations around records retention and access. Communications, meeting minutes, maintenance records, and legal correspondence must be maintained. If the software tools used to capture and archive those records silently fail, the exposure falls to the corporation and its directors.
This is not a hypothetical risk. The deadline is published. The mechanism is documented. The final shutdown will not be extended. Many boards have not been briefed on this, and many property managers remain unaware. The responsibility for raising the issue falls to those who are paying attention.
What the assessment involves
Identifying exposure at a given site is straightforward for anyone with access to the Microsoft 365 administrative environment. Microsoft has published EWS usage reports within the Microsoft 365 admin centre that identify which applications in a tenant are actively using EWS. A review of those reports, combined with confirmation from software vendors on their migration status, is sufficient to determine where a condominium corporation stands.
The conversation with each vendor is simple: has your platform migrated from EWS to Microsoft Graph, and if not, what is the timeline? Most major platforms serving the Ontario residential condo market have addressed this or are actively working on it. The risk concentrates in older integrations, custom-built tools, and platforms where vendor communication has been absent.
The window before the end of August is narrow. For corporations that need more time on a given application, keeping it running past October takes a simple administrative step in Exchange Online; however, someone has to initiate it.
The question worth asking now
If a condo corporation uses Microsoft 365 or Exchange Online, and depends on any third-party software that connects to it, one conversation with your IT provider or property manager is sufficient to know where you stand.
The deadline is fixed. The failure mode is silent. The preparation window is open, but not for much longer.
Aaron Lazare is the owner of Toronto Tech, an independent IT advisory firm working exclusively with residential condominium corporations in the GTA. He can be reached at [email protected] or torontotechguy.com.
