Microsoft has begun swapping OpenAI and Anthropic models for its own MAI systems in Excel and Outlook, a shift aimed at curbing its fast-growing artificial intelligence bill.

Tens of thousands of prompts in the two applications now run each week on Microsoft’s internally built models.

Why Microsoft Wants to Cut Its AI Bill

Microsoft consumes huge volumes of AI tokens across products such as its Copilot assistant. It currently gets much of that computing at a discount through a long-standing partnership with OpenAI.

That arrangement will not last forever. AI chief Mustafa Suleyman’s team wants to avoid paying whatever leading labs charge once the discount ends.

Bloomberg, citing a person familiar with the work, reported that Excel and Outlook had previously leaned more on OpenAI and Anthropic. Now, MAI usage accounts for a small share of overall AI activity.

In June, Suleyman said Microsoft was trying to cut spending on Anthropic by using more of its own systems. His comments framed the internal effort 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.

This follows earlier signs of an enterprise AI cost squeeze at the company. Microsoft began winding down most internal Claude Code licenses in mid-May 2026. 

Meanwhile, the model switch forms part of a wider cost push at Microsoft. The company is trimming spending even as it pours record sums into AI.

BeInCrypto reported that Microsoft is cutting 2.1% of its workforce, or 4,800 jobs. Its Xbox unit absorbed major reductions, with roughly 3,200 roles set to go.

Source: BeInCrypto