Microsoft adds GPT‑5.6 to 365 Copilot and unveils Copilot Cowork assistant

Microsoft announced that its latest flagship AI model, GPT‑5.6, will become the priority engine for Microsoft 365 Copilot across Word, Excel, PowerPoint, Outlook and Teams. The model is designed to deliver higher token‑processing efficiency and stronger performance on complex tasks, allowing users to create documents, analyse data and build presentations with fewer prompt revisions. As part of the same rollout, Microsoft introduced a preview of Copilot Cowork, an autonomous assistant that coordinates work across departments and projects.

The update, scheduled for automatic deployment beginning 9 July 2026, requires no administrator configuration. Microsoft cited comments from Nitin Agrawal, Copilot & Agent Core President, and OpenAI’s API product lead Nikunj Handa, highlighting the expected productivity gains for millions of Office users. Technical details note that the GPT‑5.6 suite includes the Sol model, which outperforms prior versions on benchmark tests. The rollout also addresses emerging security concerns, such as device‑code‑flow attacks, by offering the Entra Backup and Recovery service that can restore data within seven days.