# Customer Response
This object defines a customer in your system. Use it to manage customer profiles, save payment methods and contact details.
## Structure
`CustomerResponse`
## Fields
| Name | Type | Tags | Description | Getter | Setter |
| --- | --- | --- | --- | --- | --- |
| `id` | `?string` | Optional | The unique ID for a customer generated by PayPal.
**Constraints**: *Minimum Length*: `1`, *Maximum Length*: `22`, *Pattern*: `^[0-9a-zA-Z_-]+$` | getId(): ?string | setId(?string id): void |
| `merchantCustomerId` | `?string` | Optional | Merchants and partners may already have a data-store where their customer information is persisted. Use merchant_customer_id to associate the PayPal-generated customer.id to your representation of a customer.
**Constraints**: *Minimum Length*: `1`, *Maximum Length*: `64`, *Pattern*: `^[0-9a-zA-Z-_.^*$@#]+$` | getMerchantCustomerId(): ?string | setMerchantCustomerId(?string merchantCustomerId): void |
## Example (as JSON)
```json
{
"id": "id4",
"merchant_customer_id": "merchant_customer_id6"
}
```