A concatenated UCC/EAN Code 128 Service barcode with unique Service Type Code “55” or Intelligent Mail package barcode is required on all Priority Mail Open and Distribute container address labels. These labels can be obtained through a service software developer at www.usps.com/business/shipping-systems-providers.htm, through the USPS Click-N-Ship for Business® desktop application at www.usps.com/business/click-n-ship-for-business.htm, or by integrating the USPS Web Tools Application Program Interface using your own developer at https://www.usps.com/business/web-tools-apis/welcome.htm.
