QSA

QSAs (Qualified Security Assessors) are companies and professionals who are certified by the PCI SSC to perform PCI DSS on-site assessments. Typically, the assessor completes an audit to identify whether your organization is compliant, and they can help with your Report on Compliance, Self-Assessment Questionnaire or Attestation of Compliance.

External security assessments are undertaken by ASVs.

Refer to the QSA Qualification Requirements for details about requirements for QSA Companies and Employees. You can find a QSA here.