# Customer

Customer service provides a set of APIs used for storing and managing shoppers' personal details and contact information in a single place. Each stored customer is represented by an `id` which can be attached to the request of other Verifone services, where customer details can be provided (e.g. Checkout or 3DS services).

**Field restrictions:**

Special characters permitted on all parameters: +\_-',. within the customer API parameters.

Permitted Special Characters:  / : ; ' - ! “ # $ % & ( ) \* < = >  ? @ \[ ] ^ \` { | } \~

Disallowed Special Characters: \\

**Customer requirements for 3DS payments:**

To place a 3DS transaction with a customer object, please review the parameter restrictions listed [here](https://docs.verifone.com/online-payments/checkout/accepting-payments/3d-secure-payments).

You can download the full API spec below:

{% file src="/files/PB4LBVX6FKyRDFZdxDY8" %}


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