amazon vendor central sign up typically occurs through an invitation process for brands and distributors wishing to sell directly to Amazon. Once onboarded, vendors can manage purchase orders, upload content, and track operational metrics using the dedicated Vendor Central portal. The sign-up process involves validation of business credentials and negotiation of supply agreements. Joining this program can provide more stable purchase volumes and increased visibility, though vendors also relinquish pricing control and take on additional logistical responsibilities.