Microsoft says that Office 365 (and Microsoft 365) services including Exchange Online, SharePoint Online, and OneDrive for Business will require versions of Office in mainstream support starting with October 13, 2020.
This means that a smaller number of Office clients will still be provided with connectivity support, with Office 2013 and Office 2010 users potentially encountering reliability or performance problems after these versions reach their end of support.
Office 2007 also reached its end of support three years ago, on October 10, 2017, after a support lifecycle of 10 years.
For Office versions out of support, Microsoft no longer offers technical support, bug fixes for newly discovered issues, and security updates for new vulnerabilities.
According to a support document with details on connectivity to Office 365 services, the company says that only these versions of Office will still be supported after October 13:
• Microsoft 365 Apps for enterprise (previously named Office 365 ProPlus) • Microsoft 365 Apps for business (previously named Office 365 Business) • Office 2019, such as Office Professional Plus 2019 • Office 2016, such as Office Standard 2016
Microsoft says that Office 2019 and Office 2016 will be supported until October 2023, with more info on end of support dates for Office versions available in the Office configuration support matrix.
"We won’t take any active measures to block other versions of the Office client, such as Office 2013, from connecting to Office 365 services, but these older clients may encounter performance or reliability issues over time," Microsoft explains.
"After October 13, 2020, ongoing investments to our cloud services will not take into account older Office clients," the company adds.
"Organizations that use these older clients will almost certainly face an increased security risk and may find themselves out of compliance depending upon specific regional or industry requirements.
"Therefore, administrators should update older Office clients to versions of Office supported for connecting to Office 365 services."
End dates for Office mainstream support (Microsoft)
Microsoft will also deprecate TLS 1.0 and 1.1 in Office 365 starting with October 15, 2020, after temporarily suspending deprecation enforcement for commercial customers due to the COVID-19 pandemic.
Basic Authentication's removal from Exchange Online was also postponed until the second half of 2021 due to the pandemic, however, Microsoft will still automatically disable Basic Authentication for all newly created tenants and for those with no recorded usage starting October.
Customers who want to avoid the inherent problems that will arise for users trying to connect to Office 365 services using unsupported Office clients are recommended to upgrade to the latest Office versions:
• Office 2019 — a one-time purchase and available for one computer per license.
• Microsoft 365 Apps — the subscription version of Office that comes with many Office 365 (and Microsoft 365) enterprise and business plans.
However, if you decide to upgrade, it is important to mention that Office 2019 has the same feature set since its release date in October 2018, while the subscription-based Microsoft 365 Apps is updated with new features regularly.