Payment Card Industry Data Security Standards (PCI DSS) is a global data security standard to protect confidential payment card information against theft. Airlines have demanded that IATA support their own internal compliance project by making the BSP card sales channel PCI DSS compliant. This is why IATA-Accredited Travel Agents now need to become PCI DSS compliant.
On this page you will find the procedure to follow to comply with this standard.
http://www.iata.org/services/finance/Pages/pci-dss.aspx