ShipStation can apply various actions to multiple orders and shipments in bulk.
To apply a bulk action, select the orders in the Orders grid you wish to modify. Then click on one of the Action Menu buttons or select an action from the Bulk Update drop-down menu.

Once you select the desired action, follow the instructions on the screen to complete it. ShipStation will then apply the update to all selected orders.
From the Bulk Update drop-down menu, you can:
Set Ship by Date
Add a Note
Apply Shipping Preset
Service
Package
Weight
Size
Ship From
Insurance
Confirmation
Do Not Notify Marketplace
Email Template
Packing Slip Template
Other Shipping Options
With the Action buttons, you can do the following to orders in bulk:
Hold
Tag
Assign To
Print > Packing Slip
Print > Pick List
Print > Order Summary
Other actions > Mark as Shipped