Intelligent Mail Barcodes (IMb) – What Are They and Why Are They Important?

You’ve already seen Intelligent Mail barcodes. Whether you work in the printing and mailing industry, or simply receive mail at home, an Intelligent Mail barcode has passed through your hands. To many people, these codes may just look like a series of black lines. But what do they really consist of and why are they Important?

What Are Intelligent Mail Barcodes?

“Intelligent Mail” is a service offered by the United States Postal Service. The service uses a 65-bar postal barcode to sort and deliver domestic mail. This unique barcode is printed on envelopes with the recipient’s address. There’s a lot of data contained in those little black bars! They identify the distribution center, the carrier route, the sender’s business mailer ID, and even the type of mail being sent (first class, standard, etc). All this data can be read automatically by the USPS mail sorting machines.

The result? Quicker, more efficient mail sorting and delivery. Since this system of barcoding shortens delivery times, it also saves the Postal Service on production costs.

What information is contained in the 65 bars that make up the Intelligent Mail barcode?

The barcode contains a great deal of information and all 65 bars are required. There are up to 31 digits encoded into 65 vertical bars. It does so with a 4–state symbology – and no, 4-state doesn’t refer to four of the 50 states, the four states refer to the size and placement of the bar, called full bar, ascender, tracker, or descender. The 31 digits are be broken down into:

• 20-digit Tracking Code, which tells us the identification of the mailer plus unique mail piece information.
• 11-digit Routing Code, which consists of the Delivery Point Zip code.

The Tracking Code, or first 20 of the 31 digits, can be further broken down into:

• Barcode Identifier (BI) – Required, 2 digits.
• Service Type Identifier (STID) – Required, 3 digits.
• Mailer ID (MID) – Required except in the case of Origin IMb Tracing barcodes, where the Mailer ID and Serial Number fields are combined. The MID is 6 or 9 digits.
• Serial Number – Required when Origin IMb Tracing is not used. It is 6 or 9 digits depending on the length of the MID, as the two together total 15 digits.

The 11-digit Routing Code consists of:

• The Delivery Point Zip code is 0, 5, 9 or 11 digits (depending upon the amount of routing information). Mailers may choose not to populate this field. The terms “Delivery Point ZIP code” and “Routing Code” can be used interchangeably.

As you can see, there’s a lot to learn about Intelligent Mail Barcoding. If you’re feeling overwhelmed, have additional questions, or simply want to make sure you get the most out of Intelligent Mail, contact us today. We’ll put our expertise to work for you!