Google Policies and Requirements

Make sure that your website is compliant with Google's policies

Google Shopping Policies: https://support.google.com/merchants/answer/188484

User Safety Policy: https://support.google.com/merchants/answer/2768342
Billing Policy: https://support.google.com/merchants/answer/2704226?hl=en

Sites must contain the following pages:
Return/Refund Policy
Payment Options / Payment policy
Terms and Conditions
Shipping Policy

The links in the footer of your site should be very visible.