# Create/Update Order

You can use this method to create a new order *or* update an existing order. If the `orderKey` is specified, ShipStation will attempt to locate the order with the specified `orderKey`. If found, the existing order with that key will be updated. If the `orderKey` is not found, a new order will be created with that `orderKey`.

For **split orders**, [see the `mergedOrSplit` property in Advanced Options](/apis/shipstation-v1/docs/models/advanced-options). This property (key) is always required for merged or split orders.

This call does not currently support partial updates. The entire resource must be provided in the body of the request.

> **NOTE** Only orders in an open status in ShipStation (`awaiting_payment`,`awaiting_shipment`, and `on_hold`) can be updated through this method. Orders in the `cancelled` and `shipped` states may not be updated. The body of this request should specify an [**Order**](/apis/shipstation-v1/docs/models/order) object.


## Related Resources

- [Order Model](/apis/shipstation-v1/docs/models/order)
- See all order endpoints in the [Full API Reference](/apis/shipstation-v1/openapi)