UPS tracking number rules

The UPS order number is composed of: 1Z XXX XXX YY ZZZZ ZZZC
• X = Shipper’s UPS account number (6 digits)
• Y = UPS service level number (2 digits) (the specific meaning will be listed below)
• Z = package identification number (7 digits)
• C = Check digit 
UPS service level code meaning (i.e. the Y character above)
• 01 UPS United States Next Day Air (“Red”) – UPS next day delivery (air transport, red order)
• 02 UPS United States Second Day Air (“Blue”) – Delivered by the end of the second UPS business day (air freight, blue bill) 
• 03 UPS United States Ground – UPS ground transport
• 12 UPS United States Third Day Select UPS delivers by the end of the next business day
• 13 UPS United States Next Day Air Saver (“Red Saver”) – UPS next day delivery (air freight, red bill, discount version)
• 15 UPS United States Next Day Air Early AM – UPS Next Day Air Early AM
• 22 UPS United States Ground – Returns Plus – Three Pickup Attempts – UPS Ground (up to three pickup attempts)
• 32 UPS United States Next Day Air Early AM – COD – UPS Next Day Air (Cash on Delivery)
• 33 UPS United States Next Day Air Early AM – Saturday Delivery, COD
• 41 UPS United States Next Day Air Early AM – Saturday Delivery
• 42 UPS United States Ground – Signature Required – UPS Ground (signature required)
• 44 UPS United States Next Day Air – Saturday Delivery
• 66 UPS United States Worldwide Express – UPS Worldwide Express (1-3 business days delivery)
• 72 UPS United States Ground – Collect on Delivery
• 78 UPS United States Ground – Returns Plus – One Pickup Attempt – UPS Ground (only one delivery)
• 90 UPS United States Ground – Returns – UPS Prints and Mails Label – UPS Ground (print return label)
• A0 UPS United States Next Day Air Early AM – Adult Signature Required – UPS Next Day Air Early AM (Adult Signature Required)
• A1 UPS United States Next Day Air Early AM – Saturday Delivery, Adult Signature Required – UPS Next Day Air Early AM – Saturday Delivery, Adult Signature Required
• A2 UPS United States Next Day Air – Adult Signature Required – UPS Next Day Air (Adult Signature Required)
• A8 UPS United States Ground – Adult Signature Required – UPS Ground (Adult Signature Required)
• A9 UPS United States Next Day Air Early AM – Adult Signature Required, COD – UPS Next Day Air (Adult Signature Required, Cash on Delivery)
• AA UPS United States Next Day Air Early AM – Saturday Delivery, Adult Signature Required, COD – UPS Next Day Air (Saturday delivery, adult signature required, cash on delivery)