The customer's resource represents a customer of your business. All cards, payments and transactions are linked back to the customer_id.

Customer object example:

{
    "customer_id": "4f3970f9-3cf8-424d-299e-631dea1b7d30",
    "company_id": "a36c8fdb-bec8-c121-ac30-9cc41878f3d7",
    "reference": "customer_number_00989",
    "first_name": "Edward",
    "last_name": "Jones",
    "dob": "1988-10-03",
    "billing": {
        "address": {
            "line_1": "152 Aldgate Drive",
            "line_2": "",
            "city": "London",
            "state": "",
            "postcode": "E1 7RT",
            "country_code": "GB"
        },
        "email": "[email protected]",
        "phone": {
            "number": "2039826580",
            "country_code": "44"
        }
    },
    "shipping": {
        "address_match": false,
        "address": {
            "line_1": "152 Aldgate Drive",
            "line_2": "",
            "city": "London",
            "state": "",
            "postcode": "E1 7RT",
            "country_code": "GB"
        },
        "email": "[email protected]",
        "phone": {
            "number": "2039826580",
            "country_code": "44"
        }
    },
    "custom_data": "L3BheW1lbnQtbGlua3MgcGF5IGN1c3RvbV9kYXRh",
    "ip": "127.0.0.1"
}