IT Admin Change Calendar Microsoft 365

Skype for Business Server 2015 and 2019 reached end of support on October 14, 2025

Skype for Business Server 2015 and 2019 reached end of support on October 14, 2025. Plan migration to Teams or a supported platform.

CriticalEnd of supportAction requiredIn effectVerified

Product

Skype for Business Server

Announced

18 June 2024

Effective from

14 October 2025

Who is affected

Organizations still running on-premises Skype for Business Server 2015 or 2019 for enterprise voice, IM, and presence.

Admin roles to involve: Unified communications admin, Infrastructure admin, Security admin

What administrators should do

Plan migration of on-premises Skype for Business Server 2015 / 2019 (IM, presence, voice) to Microsoft Teams or another supported platform. After October 14, 2025 there are no security fixes or support. Microsoft's June 2024 roadmap update says Skype for Business Server SE would be available shortly before Skype for Business Server 2015 and 2019 reached end of support on October 14, 2025.

What happens if this is ignored

The servers keep running but receive no security updates, leaving voice and messaging infrastructure exposed to unpatched vulnerabilities.

Why this is rated critical: severity comes from a fixed rubric — this entry is a end of support that requires administrator action. Time-to-deadline is shown separately and never changes the rating.

Official source

Skype for Business Server Roadmap Update

Published by Microsoft · Source dated 18 June 2024 · Checked 24 August 2026

Last verified 24 August 2026