USPS Tracking Barcode and Label Changes


With the January 2, 2014 release of our Endicia software, we began using a new USPS barcode protocol called Intelligent Mail Parcel Barcode or IMpb, for short. If you had been using Delivery Confirmation in the past, the new barcodes look pretty much like the old ones, but the data payload has changed. For domestic Priority Express Mail users, you will notice that the IMpb tracking number looks identical to the Delivery Confirmation barcode seen on other mail classes. Gone is the old alphanumeric "EO123456789US" Express Mail format—so that is a very noticeable change.

In contrast, tracking numbers on USPS international packages have not changed as their format is defined for all the Post’s worldwide by the Universal Postal Union in Bern Switzerland.

The IMpb Barcode Structure

Let's look at the new barcode structure shown in Figure 1. The barcode begins with a “420” followed by the 5 digit ZIP of the destination. You don’t actually see these two numbers in the human readable data below the barcode (see Figure 2), but they are part of the barcode itself. The prefix is use to route the package in the USPS main plants. So you see that the IMpb barcode actually combines routing and tracking!

The next two digits are always a 94, which means that this label was created by a PC Postage vendor. Next is a very important 3-digit "service code". Prior barcodes had a 2-digit service code—the IMpb adds one more digit. The USPS has a published list of service codes in USPS Publication 199. There are hundreds of possible service codes. They essentially cover all possible permutations of USPS services. For instance, there is a different service code for a Priority Mail package with Delivery Confirmation and insurance. There is another service code for First-Class Mail with Delivery Confirmation and Restricted Delivery. So, the new 3-digit Service Type Code (STC) encapsulates the mail class and any and all extra services.

IMpb Data Payload
Figure 1: IMpb Data Payload

The next two digits are a source identifier. The number 10 uniquely identifies Endicia as the PC Postage provider. Next is a Mailer ID (MID). MID's are assigned by the USPS to identify the originator of the barcode. Because our loyal Endicia customers create millions of barcodes per day, we were given several special 6-digit MID’s (the one shown is the example barcode is 200793). When using a 6-digit MID, we employ the 10 for the source identifier and we can generate up to 100 million unique tracking numbers.

Some of our customers have been assigned their own MID by the USPS, and, for those customers, we generate barcodes using their MID. These MID’s are usually 9 digits in length. With a 9-digit MID, you can generate up to 100,000 unique tracking numbers (and this is the situation where we use the “15” for a source identifier).

Our goal with domestic tracking numbers is to maintain uniqueness for at least 6 months. So, you may see tracking numbers “re-used” but always with a gap of at least 6 months.

So there you have it. You can now read and understand the domestic tracking barcodes!

Priority Mail Label with STC of 055
Figure 2: Priority Mail Label with STC of 055

Consolidating Legacy USPS Barcodes into the IMpb

A major benefit of this 3 digit STC is that USPS can reduce the number of barcodes on a package or mail piece. If you’ve ever done COD, Certified Mai, Insured, or Registered Mail, you know that each of these services use a distinct barcode. But with IMpb, these services can be represented with a single barcode which also provides the tracking function. This unification is depicted conceptually in Figure 3.

The IMpB Eliminates the Need for Old-Style Special Service Barcodes
Figure 3: The IMpB Eliminates the Need for Old-Style Special Service Barcodes

USPS special services are often indicated by colored labels. These colors help the USPS operational staff identify pieces that need special handling. In the future, you will likely see these colors disappear as the impact of the IMpb becomes more pronounced inside USPS operations. In the transitional period, USPS is creating colored labels representing the various special services but without any special barcodes. Figure 4 is an example of a Registered Mail label with a new red Label 200N which is similar to the old Label 200 which carries its own barcode. This was created using DAZzle with the Label 200N added as an image and then printed on a color printer.

Eliminating multiple barcodes on packages reduces confusion in the USPS operational stream and speeds preparation of the packages by the shipper. Perhaps more importantly, the shipper doesn’t have to keep track of two different identifying numbers for each package — each often reported via different data streams.

Registered Mail Label with Priority Mail
Figure 4: Registered Mail Label with Priority Mail. Notice the
Banner Above the Barcode and the Service Code of 098.

Goodbye “USPS Delivery Confirmation” Hello “USPS Tracking #”

The text banners above the barcode on your labels magically changed with the Jan. 2, 2014 release. For instance, where the “ZIP-USPS Delivery Confirmation” text appeared, you now see “USPS Tracking #”. Even “ZIP - USPS Signature Confirmation” changed to “ZIP - USPS Tracking #”. No need to update your copy of DAZzle or Endicia for Mac—the banner text simply changed one day (spooky, huh?).

The rewording reflects the USPS's continuing commitment to provide better package visibility during the delivery cycle. When Delivery Confirmation started around 2000, you got just that—a single scan indicating the delivery event. Now, you will typically see over 10 scan events for a given package, so “tracking” is a more accurate description of what the barcode does. The new banners above the barcode announce what services are required at delivery, and, the delivering carrier will be additionally alerted when he or she scans the barcode. The scanner gun will tell him or her exactly what actions are needed.

What are Those Weird 4 Digit Numbers on My Label?

More numbers have popped up on shipping labels — in particular two 4-digit numbers. One number is called the Retail Distribution Code (RDC) , the other is the Carrier Route number (CRT). You can see them on the labels in Figures 2 and 4.

The carrier route is the number in the small rectangular box. This is used to sort packages at the destination Post Office just before the carrier goes out to make his or her deliveries. Each Post Office divides the routes that they service by numbers. C004 means carrier route #4. R008 means rural route #8. In the past, USPS operations staff had to look at each delivery address and make this connection by memory. Now they just look at the number in the box.

The RDC (not in a box) is used by your local origin Post Office to do a preliminary package sort. Your local Post Office prepares containers every evening that are filled with packages heading to the nearest USPS processing "plant". For instance, Endicia’s local Palo Alto, California Post Office forwards mail to the San Francisco Sectional Center Facility (SCF) every evening. The RDC code lets the Palo Alto dock workers perform a first-level sort so that packages destined for the San Francisco Bay Area would go into one container and those packages going to the East Coast would be in another container. Previously, they sorted by looking at the ZIP Code of the address and then figuring out what container would be appropriate. Now, they can just sort based on the simple RDC code and save a ton of time. This preliminary sort at the inducting Post Office speeds up the processing at the main plant hours later.

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