Microsoft plans to pay Anthropic over $2 billion annually to integrate Claude AI models into its Copilot assistant. This decision follows performance issues with the tool, particularly within Microsoft Office applications, which prompted the company to incorporate Anthropic models in the summer of 2025.
Executive Vice President Charles Lamanna led the initiative, demonstrating that Claude models improved output for tasks like financial automation in Excel and presentation creation in PowerPoint. Currently, more than 30 million corporate users utilize Copilot, a figure that has more than doubled since early 2026.
To manage costs, Microsoft utilizes an internal model router that directs requests to the most economical AI model. Earlier in 2026, Microsoft reduced its annualized spending on Anthropic by over 33% from a peak of roughly $1 billion. The company continues to use OpenAI models alongside Claude to protect margins.
Beyond the annual payments for model usage, Microsoft maintains a broader financial relationship with Anthropic. This includes investments of up to $5 billion and a commitment of $30 billion tied to Azure services. Microsoft remains the primary partner for OpenAI while expanding its role as a major Anthropic client.
