What is a Tracking Number?
Tracking numbers are used by UPS to identify and trace shipments as they move through the UPS system to their destination. UPS automatically assigns a tracking number to your shipment.
UPS tracking numbers appear in the following formats:
UPS will also track the following types of tracking numbers, which contain from seven to 20 characters:
UPS Mail Innovations Tracking Numbers
UPS Mail Innovations® uses tracking numbers to identify and track shipments as they move through the UPS Mail Innovations network and the United States Postal Service®, which makes the final delivery. With your tracking number, you can track your UPS Mail Innovations piece on both ups.com and upsmi.com. UPS Mail Innovations tracking numbers differ from a small package reference number in length and terminology.
UPS Mail Innovations tracking numbers appear in the following formats:
Sequence Number (MMS/MMI Number): an 18-digit number assigned internally by UPS
MIXXXXXXNNNNNNNNNNNNNNNNNNNNNN
This indicator is made up of the following three components:
NNNNNNNNNNNNNNNNNNNNNN - a unique number, up to 22 characters, assigned by the shipper to identify a mail piece. Use alpha and/or numeric characters with no spaces or symbols. The same ID should not be reused for other mail pieces for at least six months.