# Pass a buyer identifier to streamline buyer login (/v5/checkout/pass-buyer-id)



You can pass a buyer's email address as the buyer identifier to PayPal through the Create Order request. During one-time checkout, PayPal uses this email address to prefill the buyer's PayPal login page. This streamlines and quickens the buyer authentication process for an effortless login.

## How it works [#how-it-works]

In your app, when you [Create an order](/v5/checkout/one-time#2-create-an-order), as part of the request body, send the buyer’s email address in the `payment_source.paypal.email_address` field. For more information, see [Create Order API](/api/orders/v2/orders-create/#request-body) request.

```javascript lineNumbers
curl -v -X POST https://api-m.sandbox.paypal.com/v2/checkout/orders \
-H 'Content-Type: application/json' \
-H 'PayPal-Request-Id: REQUEST-ID' \
-H 'Authorization: Bearer ACCESS-TOKEN' \
-d '{
    "intent": "CAPTURE",
    "payment_source": {
        "paypal": {
            "email_address": "customer@example.com",
            "experience_context": {
                "shipping_preference": "GET_FROM_FILE",
                "user_action": "PAY_NOW",
                "return_url": "https://example.com/returnUrl",
                "cancel_url": "https://example.com/cancelUrl"
            }
        }
    },
    "purchase_units": [
        {
            "invoice_id": "005384",
            "amount": {
                "currency_code": "USD",
                "value": "40.00"
            }
        }
    ]
}'
```

After a successful request, the passed email address is used to prepopulate the PayPal login page when the buyer pays with PayPal.