Reserving Inventory
Inventory for each prepaid subscription order cycle is reserved when the fulfillment date is reached.
The entire subscription order is not reserved when the order is created.
To reserve inventory for a scheduled fulfillment before the fulfillment date, you can fulfill a scheduled order early.
Fulfilling a prepaid subscription order
When a scheduled order reaches its fulfillment date, the status of the order updates to Unfulfilled and you can fulfill the order.
Fulfilling a prepaid subscription order early
You can't reschedule scheduled fulfillments, but you can choose to fulfill an order early.
On Shopify Admin
From your Shopify admin, click Orders
Select the order that you want to fulfill early
In the Scheduled section, click Fulfill early
Review the order fulfillment information, and then click Mark as unfulfilled. The order status is updated to Unfulfilled and you can fulfill the items.