Short answer
If your products are fulfilled by Fourthwall’s partners, shipping options are automatically calculated and can’t be changed manually.
More details
Fourthwall determines the best shipping method and carrier based on the customer’s location and the product type. If an order contains multiple items, they may ship separately depending on how and where each item is fulfilled. This is why some orders may show a Partially Shipped status.
While items in the same order can ship at different times automatically, shipping options and shipment timing can’t be manually changed after an order is placed. Once production begins, orders can’t be expedited, modified, or intentionally split into early and later shipments on request.
For print-on-demand apparel, production starts after checkout, and timelines vary by product and fulfillment partner. Tracking information becomes available only after each shipment leaves the facility. Urgent or next-day delivery requests can’t be guaranteed, even if the order was placed several days in advance.
If you’d like to control shipping methods or offer custom options like Priority Mail, this is only possible for self-fulfilled products. To do this, set the fulfillment type to I’m shipping orders myself and connect ShipStation to manage fulfillment.