Here's a video explaining the CSV import process:
ShipStation allows you to import orders via CSV( or via tab-delineated value) into a manual store. Most shopping carts and marketplaces will allow you to export your existing orders in one of these two types of formats.
While you're looking through your CSV, make sure that all your Order #s are unique (to both others in the document, and those in ShipStation), otherwise ShipStation will try to update the previous matching order number. If you want your order numbers to automatically number themselves on your store, you can put "AUTO" as the value for each order in your CSV.
When you're ready to import, head to to the Orders tab in ShipStation. Then, click on the Other Actions dropdown and select "Import Orders."
If you'd like to see a full list of the fields available for you, and which ones are required, you can take a look at the PDF at the bottom of this page.
This will show the page to set up your import. Here, you need to select the file from you computer, and then choose the manual store into which you wish to import the orders.
First, click and locate the document containing your orders and click Open.
Once it uploads, you'll see the file name listed in the upper righthand corner:
Next, you'll select the store you want to import these orders to as well as select whether or not to save the Field Mapping.
Finally, choose between the CSV file or the Tab delimited file that we talked about earlier, select whether the file has column names at the top, and then click Upload and Continue.
(Also, most character sets used will be "UTF-8". More or less, if you aren't sure if you need to use "UTF-8" or "ANSI", go with "UTF-8".)
Now, you'll need to go through and select the appropriate column from your CSV header and match it to the ShipStation field.
Once you've mapped all of the fields, you have the option to save the settings for future imports.
To save the settings, simply name the mapping.
Now, click Start Import and the system will process the import. Once it's finished, your orders should be imported into the "Awaiting Shipment" section of your orders screen.
If you need some help with formatting your CSV (especially for orders with more than one item in it), you can format your file after the one attached below.