Microsoft Will Use Anthropic Models in Office 365 Copilot

Microsoft plans to buy access to Anthropic’s artificial intelligence (AI) models for parts of Office 365 Copilot, partly reducing its reliance on OpenAI, The Information reported.

Under the plan, Microsoft will blend Anthropic’s Claude models with OpenAI’s technology inside Word, Excel, Outlook and PowerPoint. People involved told The Information that Anthropic’s latest models performed better at advanced tasks, such as automating financial functions in Excel and generating PowerPoint presentations from user instructions.

Microsoft aims to announce the change in the coming weeks, while keeping Copilot pricing at $30 per user per month. OpenAI models will continue to power other Copilot features.

The shift follows months of sometimes tense talks over OpenAI’s plan to restructure its for‑profit arm, though Microsoft’s product leaders also found Anthropic’s Claude Sonnet 4 outperformed OpenAI in “subtle but important” ways like producing more polished slides, the report said.

OpenAI’s newly launched GPT‑5 is a quality step up, according to The Information, but Microsoft will pay to access Anthropic models through Amazon Web Services because those models are hosted on AWS.

Microsoft hasn’t disclosed Office Copilot sales. The company has said more than 100 million customers use at least one Copilot product, and analysts estimate Office Copilot is pacing above $1 billion in annual revenue.

“As we’ve said, OpenAI will continue to be our partner on frontier models and we remain committed to our long‑term partnership,” a Microsoft spokesperson said.

PYMNTS recently reported that Anthropic added native file creation to Claude, including spreadsheets and slide decks, as it pushes deeper into enterprise work: “This transforms Claude from an adviser into an active collaborator,” the company said. PYMNTS has also noted Microsoft’s AI infrastructure build-out, writing that the company “expanded its data center footprint to more than 400 sites in 70 regions.”

The rest of the story: Microsoft’s move underscores a multimodel strategy that already includes using Anthropic for advanced agent features in GitHub Copilot and exploring alternative models for consumer Copilot, according to The Information. Anthropic’s models are hosted on AWS, where Microsoft will pay to access them even as its long‑term OpenAI tie allows use of OpenAI models at no extra cost. Internally, executive Charles Lamanna is leading the Office integration effort.

Both Anthropic and OpenAI are building their own workplace apps that compete more directly with Microsoft’s productivity suite, and third parties are tapping Anthropic to automate spreadsheets. Some customers have been hesitant to pay more for Office AI after bugs in experimental features like PowerPoint deck generation and Excel editing, a gap Microsoft is betting Anthropic can help close.