The United States Postal Service (USPS) is one of the most common and cost-effective ways to ship items within the United States.  The service is also available for carrying products internationally.  By default, the shipping extension for the USPS is loaded, but it is not installed.  The following tutorial will guide you through installing and configuring the shipping extension in OpenCart 1.5.

Installing the United States Postal Service Shipping Extension

1. Login to the Administrator Dashboard
2. Hover over the menu bar where it reads EXTENSIONS.  Click on SHIPPINGwhen it appears in the drop-down menu. You will see the following screen or something similar (screenshot is from Opencart 1.54)

   

   
   The screen shot above shows the USPS option as second from the bottom in the list.  Click on INSTALL to start the installation process.

3. The installation should not take very long and the ACTION column will change after it is complete.  You will see the options for EDIT and UNINSTALL appear when it has finished.  Click on EDITin order to begin the configuration of the shipping extension.

   

   In order to properly configure the USPS extension, you must have a USPS Web Tools account. Click on this link to register:  USPS Web Tools Registration
   
   

   User ID	ID created with USPS account
   Zip Code	Zip/Postal code of shipper
   Domestic Services	Shipping services available within the country
   International Services	Shipping services available for shipping outside of the country
   Size	Regular or Large packages
   Container	Rectangular, non-rectangular or variable package shapes
   Machinable	Are packages able to run through machinery? yes or no?
   Dimensions (LxWxH)	Average side of packages
   Display Delivery Time	Show delivery time
   Display Delivery Weight	Show delivery weight
   Weight Class	Must be set to pound
   Tax Class	Applies none, taxable goods, and downloadable products
   Geo Zone	Determines the geographical zone
   Status	ENABLES  Extension
   Sort Order	Determines the position of the shipping
   Debug Mode	Used to save logs that are in i

   
   

Once the shipping extension has been installed with your USPS registration information, you will be able to provide the shipping option to your customers.  If you are using more than one carrier make sure to clearly specify its availability per the region where it is available.