First, let's explain the term Qualified Security Accessor.
A Qualified Security Accessor (QSA) is a person approved by the PCI Security Standards Council to audit merchants for compliance with the Payment Card Industry Data Security Standard.
The primary purpose of a person holding the PCI QSA certification is to assess a company that processes credit card data against the high-level control objectives of the PCI Data Security Standard (PCI DSS).
The lists of Qualified Security Assessor (QSA) and Approved Scanning Vendor companies can be accessed from the websites below:
https://www.pcisecuritystandards.org/assessors_and_solutions/approved_scanning_vendors
The correct term and related roles
The term used by the PCI Security Standards Council is Qualified Security Assessor, that is, an “assessor”. Companies that pass the quality assurance process hold this title. Organizations with a high volume of card transactions have their compliance audit carried out by one of these companies.
The Council also maintains an Approved Scanning Vendor (ASV) list. ASVs perform external security scans of internet-facing systems. Merchants and service providers have these scans performed quarterly, according to their level.
When choosing a company, references, experience and whether it provides services in Türkiye should also be checked.
