Printing Shipping Labels
While Zen Cart doesn’t provide a Carrier Shipping Label service/feature, here are some options to consider.
In some cases the Packing Slip, which you can print from your Admin screens, can be used directly on the package, or in a windowed-envelope affixed to the package.
Printing Labels from PayPal
One little-known tip is that PayPal’s Ship Now feature allows you to Pay for and Print shipping labels from your account on their website. You enter the details of the shipment (address, package dimensions), select a service, pay for it, and they provide you the label for printing. Their fees are often better than many of the other companies providing broader services.
There are some plugins which interact with the shipping/carrier companies to allow submission of orders, retrieval of tracking numbers, etc. Many do not charge any extra fee for this ability beyond the actual shipping cost. Be sure to assess the company’s offer to ensure that it meets your needs.