Microsoft Swaps OpenAI & Anthropic for Homegrown MAI in Excel and Outlook to Slim Its AI Tab 🪙

Microsoft has begun routing tens of thousands of weekly prompts in Excel and Outlook through its internally built MAI models, replacing prior reliance on OpenAI and Anthropic as part of an effort to rein in its growing artificial-intelligence bill, Bloomberg reported.

The shift is being driven by AI chief Mustafa Suleyman's team, which wants to reduce dependence on third-party providers before discounted terms with OpenAI are renegotiated. Suleyman said the initiative is framed in blunt cost terms. "We pay a lot of money to Anthropic — so our goal is to reduce and ultimately eliminate that cost," he said in June.

Despite the change, MAI traffic still accounts for a small share of Microsoft's overall AI activity. Bloomberg, citing a person familiar with the work, noted that Excel and Outlook had previously leaned more heavily on OpenAI and Anthropic before the latest swap.

Microsoft has signaled broader AI cost discipline. The company began winding down most internal Claude Code licenses in mid-May 2026 and is trimming spending even as it increases AI investment. Separately, BeInCrypto reported Microsoft is cutting 2.1% of its workforce, or 4,800 jobs, with its Xbox unit absorbing roughly 3,200 of those roles.

No financial advice, price targets, or speculation on AI contracts, token pricing, or Microsoft's stock ($MSFT) were disclosed in the reporting.