Claude Sonnet 4.6 Comes to Microsoft 365 -- and It's Free for Millions of Users

What happened

Two significant updates dropped for Claude this week, and together they represent a major expansion of Anthropic's reach.

First, on 9 March 2026, Microsoft confirmed that Claude Sonnet 4.6 is now available inside Microsoft 365 Copilot -- meaning anyone already paying for a Microsoft 365 subscription can access one of Anthropic's most capable models directly within Word, Excel, PowerPoint, and Teams.

Second, Anthropic's model itself is worth noting in its own right. Claude Sonnet 4.6, which launched in February 2026, is the current default model for all Claude free and Pro users. It includes a 1 million token context window in beta (that is roughly 750,000 words -- the equivalent of several full novels), dramatically improved coding and computer-use abilities, and performance that previously required reaching for Anthropic's Opus-tier models.

The pricing remains the same as its predecessor: $3 per million input tokens and $15 per million output tokens via the API. Anthropic also noted that early-access developers preferred Sonnet 4.6 over Opus 4.5 -- which cost considerably more -- for most real-world office tasks.

What this means for your business

If your team uses Microsoft 365, Claude is now one click away -- no new accounts, no API keys, no separate subscriptions required.

That is a meaningful shift. Until now, using Claude in a business context meant either visiting claude.ai separately or integrating it via the API. Microsoft's distribution changes that. For many small and medium businesses, their first hands-on experience with a frontier AI model may now happen inside the apps they use every day.

The practical opportunities are immediate. Claude inside Excel can help analyse spreadsheet data and write formulas. Inside Word, it can summarise long documents, draft proposals, or review contracts. Inside Teams, it can catch up on missed conversations and draft replies.

If you have not yet explored AI inside your Microsoft tools, this is the moment to start. The friction has gone.