In Paynote, a Customer represents an individual or business you wish to engage with, and their profile is created and managed via the Paynote API. To start, create a customer profile for each new user or business you intend to transact with. After the customer is created and a funding source is linked, you can easily issue invoices, set up subscriptions, or initiate payments. On success, you'll receive a 201 response with a JSON body echoing the provided data, plus a unique user_id, status, and created_at timestamp—this user_id is your key for linking funding sources, issuing invoices, subscriptions, or initiating payments.