Opero Ship app supports using USPS, Stamps.com (USPS), and Endicia (USPS) as carriers. Using only USPS allows getting shipment rates and tracking shipments for free (no creating labels), while using Stamps.com (USPS) and Endicia (USPS) allows getting shipment rates, tracking shipments, and creating labels. This article covers the configuration of USPS.

Steps to Configure Carrier

• Create a USPS Business account.
• Sign Up for a Business Customer Gateway account using your USPS business account credentials (this will take you to the Business Customer Gateway signup page).
• Log in to the USPS Developer Portal USPS Developer Portal  (login using credentials from Step 1) using your USPS business account credentials once you have completed signing up.
• Create an App (Must be logged into USPS Developer Portal): Click the Apps button from the Menu Bar and complete the following steps to create an App:
  • Click “Add app” button
  • Enter “App Name” for your application (required). Important: The app name must be your company name or there will be issues when you try to authorize the app in later steps.
  • Check the box to accept Terms and Conditions, and Privacy Policy
  • Enter “Description” (optional)
  • Select the APIs Available (required)
  • Click “ADD APP” Button
• Retrieve your Consumer Key and Secret: Select the application you just registered and retrieve your Consumer Key and Consumer Secret from the credentials section. These credentials are required for generating the OAuth token.
• Authorize Application to Access Protected Information Resources: Navigate to the USPS Customer Onboarding Portal to authorize the client application you registered on the USPS APIs Developer Portal in order to access your information resources shared with the USPS. This includes information resources such as payment accounts, permits, CRID’s, MID’s, and subscriptions. This step is required to access all Version 3 APIs (Price Calculators and Package Tracking APIs).
• Once the APIs are enabled, open Opero Ship app, go to Ship Configuration page, and click USPS.
• Check the Active box so that this carrier is an active carrier. 
  • When a carrier is active, you are able to set carrier specific settings in the Create Shipment tab and create/ print active shipping labels. If the Active box is not checked, when you create a shipment, you will not see the carrier specific section for this carrier and you will not be able to create/print shipping labels for this carrier.
• Copy the Client Key into the Client Id field. Copy the Client Secret to the Client Secret field.