The Payment Card Industry Data Security Standard (PCI DSS) is a set of security standards to ensure all companies that accept, process, store, or transmit credit card information secure it to protect cardholders against misuse of their personal information.
The fines arising from not being PCI compliant range from $5,000 to $500,000, and are levied by banks and credit card institutions. Even for companies that are PCI compliant, continuous compliance is necessary.