What does it mean to be PCI compliant?
The Payment Card Industry Data Security Standard (PCI DSS) applies to companies of any size that accept credit card payments. If your company intends to accept card payment, and store, process and transmit cardholder data, you need to host your data securely with a PCI compliant hosting provider.
Is it mandatory to be PCI compliant?
Yes. If you are processing credit card data, it is required that you be PCI compliant.
Visit: https://www.pcicomplianceguide.org/faq/ to get the answers to all of your PCI questions.