If used with an optional access token for an anonymous session, all Orders and Carts that belong to the anonymousId are assigned to the newly created Customer.
If omitted in the request body, the [Customer](ctp:api:type:Customer) `stores` field is set to the [Store](ctp:api:type:Store) specified in the path parameter.
If the Customer has multiple active Carts, the anonymous Cart is [merged](/../api/customers-overview#cart-merge-during-sign-in-and-sign-up) into the most recently modified active Cart.
Creating a Customer produces the [CustomerCreated](ctp:api:type:CustomerCreatedMessage) Message.
If used with an optional access token for an anonymous session, all Orders and Carts that belong to the
anonymousIdare assigned to the newly created Customer.