GPT-5.6 becomes the preferred model for Microsoft 365 Copilot: OpenAI connects directly to tens of millions of enterprise desktops

On July 9, OpenAI announced that GPT-5.6 behind ChatGPT has become the preferred model for Microsoft 365 Copilot. This means that Microsoft’s flagship enterprise office products such as Word, Excel, PowerPoint, Outlook, and Teams use GPT-5.6 to drive the Copilot experience by default. Combined with Microsoft’s 30 million Copilot paid seats, this is the latest and most direct realization of the deep binding relationship between OpenAI and Microsoft.

A textbook-level binding for "model + distribution"

The essence of this cooperation is the ultimate embodiment of the two-wheel drive of "Model Capability + Distribution Channel": OpenAI provides the model and Microsoft provides the channel. 30 million paid seats means that GPT-5.6 directly reaches tens of millions of enterprise users around the world - this is not a reach through API calls, but a reach that is "installed in Office by default", and users are using OpenAI's model almost without any awareness. At the same time, Microsoft Copilot also supports multi-model options such as Anthropic and Meta, forming a strategy of "focusing on OpenAI and coexisting multiple models" - which not only locks in OpenAI, but also retains flexibility.

The turf war for enterprise office AI

From an industry perspective, this cooperation strengthens OpenAI's dominant position in the enterprise office AI market and pushes the "office software × large model" binding model to a new level. This model has particularly direct implications for the Chinese market: the binding method between large domestic office models (Alibaba Tongyi, Byte Doubao, Baidu Wenxin, etc.) and office software (WPS, DingTalk, Feishu) is highly isomorphic with "GPT-5.6 into M365" - whoever's model can become the "default brain" of office software will master the entrance to enterprise AI**. The successful sample of GPT-5.6 entering M365 provides a comparable coordinate for the domestic "model × office" binding: the value of the default entrance far exceeds any single-point API cooperation.

Several directions worth tracking in the future:

1. Proportion of preferred models: The actual usage ratio of GPT-5.6 to other models in M365 Copilot.
2. Pricing and Licensing Structure: The impact of the sharing model between OpenAI and Microsoft on the financial reports of both parties.
3. Domestic Office Model Binding: Whether WPS, DingTalk, etc. promote the "default model" strategy.
4. The tension of multi-model strategy: Microsoft supports the balancing of Anthropic and Meta models at the same time.