What is required to prove your PCI compliance is ultimately up to your merchant/acquiring bank, and it depends on several factors, including the number of transactions you process annually. If you process fewer than 6 million transactions per scheme (Visa, MasterCard) per year, you may be able to self-assess by completing one of the PCI DSS Self-Assessment Questionnaire (SAQ); this is a self-assessment tool to assess security for cardholder data.