Large Language Models (LLMs) have significantly enhanced enterprise productivity by automating various business operations, yet they pose risks related to data privacy, particularly when sensitive information is inadvertently shared with LLM APIs. To address these security concerns and comply with data protection laws like GDPR, Microsoft offers Presidio, a Python open-source framework designed to detect and anonymize sensitive data before it is exposed. The blog post details how to use Presidio for safeguarding data when integrating with APIs like OpenAI, emphasizing its core components: the analyzer and anonymizer, which work together to identify and mask personally identifiable information (PII). Various customization options for anonymization are discussed, including creating custom recognizers and using context-awareness to improve detection accuracy. The post also provides a proof-of-concept code for integrating Presidio with OpenAI, highlighting its application in anonymizing messages before they are processed by the API. For those seeking more robust, enterprise-grade solutions, the company offers advanced features such as user interface for rule definition, logging for auditing, and performance optimization to ensure efficient LLM application usage.