Shippo allows you to create up to 100 labels at one time as long as you're using the same package size for each shipment. Simply go to the Orders page, click on the checkboxes for all of the orders you’d like to print labels for, and click the green “Create labels for selected orders” button that appears at the top of the page.
You can include international and U.S. military addresses (APO/FPO/DPO) in a batch of labels, but keep in mind that defaults will be used for the customs information (contents type will be "merchandise," customs fees will be "DDU") and you must have an imported customs item in order for it to work.
During batch-creation, entering your package details is exactly the same. You’ll notice a text box in the upper right-hand corner with the title “Ship multiple orders” distinguishing that you’re creating a batch of labels.
NOTE: You can only batch-create labels for orders that have the same package dimensions. As long as the weights have been imported from your e-commerce store, the packages do not all have to have the same weight. If the weight for each of the orders in the batch has been imported from your e-commerce store, then you will see a checkbox on this page that says “Use imported weights.” If the weight has not been imported for each package, all packages in the batch must have the same weight, which you’ll enter on the above page as you normally would for a single label.
After clicking “Select shipping rates,” you’ll see each separate order listed on the next page with a drop-down menu of rates for each. You can select different rates from different carriers for different orders or you can select a single carrier and rate for all the orders from the “Change All” menu at the top of the page.
When you click “Buy labels for all Orders,” a PDF will generate that includes all labels, so you can print them all at once. You can do this by clicking “Download labels” on the next page. You can also choose to print each label individually if you prefer.
You can also return to the Orders page and select different labels to print in a batch - see this article for detailed steps. You do not have to create the labels in a batch in order to print them together.
When batch-creating labels, it helps to break up orders into groups to streamline the process further. For example, you can filter the Orders page by Shipping Method if you want to print all First Class labels together, or by Item Title to make sure the package dimensions will be the same.