# Fulfillments

A fulfillment groups order-line quantities that are prepared or shipped together.
One order can have several fulfillments, allowing split shipments and partial quantities.
Use order-line IDs, not variant IDs, when describing the shipment.

## Outstanding quantities

Read current order lines and existing fulfillment lines before creating another fulfillment.
Account for fulfillment status when deciding which quantities are still outstanding.
For a line ordered with quantity three, shipping one unit leaves two for a later shipment.
Do not submit the original quantity again from a stale screen.

## Status and tracking

Fulfillment states include `READY`, `SHIPPED`, `DELIVERED`, and `CANCELLED`.
Creation with carrier, tracking information, or `shippedAt` marks the fulfillment shipped.
Omit those fields if the intended result is a ready fulfillment.
Read the resulting status after an update instead of maintaining a separate local flag.

The order's shipment state summarizes delivery progress.
It does not establish that payment is captured or that the business order is complete.

## Inventory and external systems

Managed catalog lines have an inventory relationship; custom lines do not identify tracked catalog stock.
Reconcile your warehouse's shipment identity and quantity with Thor's fulfillment record.
After an ambiguous response, read existing fulfillments before creating another one.

Follow [Fulfill an order](/guides/operations/fulfill-order) for a partial-shipment example and [Allocation and inventory lifecycle](/concepts/inventory/allocation) for stock handling.