USPS, FedEx, and UPS Tracking Number Characteristics
Posted: Sat Jun 20, 2026 4:44 pm
@LeMark, PLEASE make this a sticky. I have received "tracking numbers" from various folks who are trying to be helpful, but send the wrong number. I have received internal receipt numbers, item product codes, address encodings, etc., instead of the actual tracking number. Usually on a receipt it is marked "Tracking Number...." Many times the USPS (post office) clerk will circle it on your receipt. UPS receipts say "Tracking number..." but in fine print, hard to see. I spent two years in the last job I retired from in the warehouse and was in charge of shipping, returns, etc. Here is the information on the three most common customer shippers.
USPS (post office) tracking numbers are unique alphanumeric sequences used to trace packages through the mail stream. They vary in length and composition depending on the specific mail class and service used. Common USPS tracking number formats include: Domestic Packages (Most Common): 22 digits long, typically starting with 90, 94, 93, 92, or 95. (Example: 9400 1000 0000 0000 0000 00) Priority Mail Express: 10 digits numeric, or 13 characters starting with two letters and ending with US. (Example: EA 123 456 789 US) Certified Mail: 20 to 22 digits, typically starting with 94. International Shipments: 13 characters beginning with two letters (e.g., CP, CJ, LC, EE) and ending with US. (Example: CP 123 456 789 US) Where to Find Them. Retail Receipts: The tracking number is printed at the bottom of your Post Office receipt. Shipping Labels: Found directly under the barcode on the mailing label. Online Postage: Provided on your Click-N-Ship receipt or third-party shipping platform (like Pirate Ship, eBay, or Shopify). Informed Delivery: You can view tracking numbers for incoming packages on your USPS Informed Delivery dashboard. Tracking Your Item. You can check the real-time status of your package on the official USPS Tracking web page by entering your exact sequence without any dashes or spaces. You can also text the tracking number to 28777. Link to follow a USPS tracking number: https://www.usps.com/
-----
FedEx tracking numbers are unique numeric or alphanumeric codes used to locate and monitor shipments. They primarily consist of purely numeric sequences. Core Characteristics: Length: Most FedEx tracking numbers are 12 digits long. Depending on the specific service level, they can also occasionally be 10, 15, 20, or 22 digits. Format: FedEx tracking numbers generally do not contain letters. Reference Tracking: In addition to the standard tracking number, you can often locate or monitor your package using the sender's Customer Reference Number or an Order Reference Number. Duration: Tracking records for FedEx Express, Ground, and Custom Critical are kept active in their system for 90 days after delivery. FedEx Freight shipment data is retained for two years. How to Track: You can use the official FedEx Tracking page to view the current location of your package, sign up for delivery alerts, or view photographic proof of delivery. Would you like to learn about: What specific FedEx tracking statuses (e.g., "In Transit," "At a facility") mean? How to use the FedEx Mobile App to intercept or reroute your package? How to track a package if you don't have your tracking number? Link to follow a FedEx tracking number: https://www.fedex.com/en-us/home.html
-----
Most standard UPS tracking numbers are 18 alphanumeric characters and begin with "1Z". A typical 1Z tracking number encodes specific routing and billing information. 1Z: Denotes the standard UPS carrier format. Characters 3–8: The Shipper Account Number; Characters 9–10: The Service Level Indicator (e.g., 01 for Next Day Air, 03 for Ground); Characters 11–17: The specific Package Identifier.Character; 18: The Checksum digit, used by systems to validate the number is accurate. Other UPS Tracking Formats: While the 1Z format is most common, UPS systems can also process several other types of tracking numbers depending on the type of freight:999999999999 (12-digit): Typically used for UPS Mail Innovations or consolidated ground shipments.T9999999999 (10-digit): Used for delivery notices left by a driver.7 to 20-Character Codes: Used for less-than-truckload (LTL) shipments, ocean freight (House Bill of Lading), or air freight (House Air Waybill).Tracking by Reference NumberInstead of a tracking number, you can also track your package by a custom Shipment Reference Number (up to 35 characters). This is usually an invoice, purchase order, or customer-defined number created by the shipper. Link to follow a UPS tracking number: https://www.ups.com/us/en/home
If in doubt - PLEASE ask the clerk behind the counter to mark or circle the tracking number on your receipt for you so you send the correct number to the person purchasing your item.
USPS (post office) tracking numbers are unique alphanumeric sequences used to trace packages through the mail stream. They vary in length and composition depending on the specific mail class and service used. Common USPS tracking number formats include: Domestic Packages (Most Common): 22 digits long, typically starting with 90, 94, 93, 92, or 95. (Example: 9400 1000 0000 0000 0000 00) Priority Mail Express: 10 digits numeric, or 13 characters starting with two letters and ending with US. (Example: EA 123 456 789 US) Certified Mail: 20 to 22 digits, typically starting with 94. International Shipments: 13 characters beginning with two letters (e.g., CP, CJ, LC, EE) and ending with US. (Example: CP 123 456 789 US) Where to Find Them. Retail Receipts: The tracking number is printed at the bottom of your Post Office receipt. Shipping Labels: Found directly under the barcode on the mailing label. Online Postage: Provided on your Click-N-Ship receipt or third-party shipping platform (like Pirate Ship, eBay, or Shopify). Informed Delivery: You can view tracking numbers for incoming packages on your USPS Informed Delivery dashboard. Tracking Your Item. You can check the real-time status of your package on the official USPS Tracking web page by entering your exact sequence without any dashes or spaces. You can also text the tracking number to 28777. Link to follow a USPS tracking number: https://www.usps.com/
-----
FedEx tracking numbers are unique numeric or alphanumeric codes used to locate and monitor shipments. They primarily consist of purely numeric sequences. Core Characteristics: Length: Most FedEx tracking numbers are 12 digits long. Depending on the specific service level, they can also occasionally be 10, 15, 20, or 22 digits. Format: FedEx tracking numbers generally do not contain letters. Reference Tracking: In addition to the standard tracking number, you can often locate or monitor your package using the sender's Customer Reference Number or an Order Reference Number. Duration: Tracking records for FedEx Express, Ground, and Custom Critical are kept active in their system for 90 days after delivery. FedEx Freight shipment data is retained for two years. How to Track: You can use the official FedEx Tracking page to view the current location of your package, sign up for delivery alerts, or view photographic proof of delivery. Would you like to learn about: What specific FedEx tracking statuses (e.g., "In Transit," "At a facility") mean? How to use the FedEx Mobile App to intercept or reroute your package? How to track a package if you don't have your tracking number? Link to follow a FedEx tracking number: https://www.fedex.com/en-us/home.html
-----
Most standard UPS tracking numbers are 18 alphanumeric characters and begin with "1Z". A typical 1Z tracking number encodes specific routing and billing information. 1Z: Denotes the standard UPS carrier format. Characters 3–8: The Shipper Account Number; Characters 9–10: The Service Level Indicator (e.g., 01 for Next Day Air, 03 for Ground); Characters 11–17: The specific Package Identifier.Character; 18: The Checksum digit, used by systems to validate the number is accurate. Other UPS Tracking Formats: While the 1Z format is most common, UPS systems can also process several other types of tracking numbers depending on the type of freight:999999999999 (12-digit): Typically used for UPS Mail Innovations or consolidated ground shipments.T9999999999 (10-digit): Used for delivery notices left by a driver.7 to 20-Character Codes: Used for less-than-truckload (LTL) shipments, ocean freight (House Bill of Lading), or air freight (House Air Waybill).Tracking by Reference NumberInstead of a tracking number, you can also track your package by a custom Shipment Reference Number (up to 35 characters). This is usually an invoice, purchase order, or customer-defined number created by the shipper. Link to follow a UPS tracking number: https://www.ups.com/us/en/home
If in doubt - PLEASE ask the clerk behind the counter to mark or circle the tracking number on your receipt for you so you send the correct number to the person purchasing your item.