Voice AI guardrails are essential tools that ensure compliance, quality, and cost efficiency in industries like healthcare, finance, and contact centers by embedding protective measures directly into transcription pipelines. These guardrails tackle three primary challenges: compliance violations, quality degradation, and operational waste, by implementing safety controls, quality filters, and efficiency measures at the API level. Safety controls automatically redact personally identifiable information (PII) to prevent regulatory breaches, while quality filters remove profanity and moderate harmful content to maintain high transcript standards. Efficiency is enhanced by filtering out low-value audio content, reducing unnecessary processing costs. The guardrails function during transcription, offering a streamlined, integrated approach that negates the need for external filters or manual reviews, thus maintaining compliance and protecting sensitive data without compromising operational workflows.