Four bar states, five data fields and up to eleven routing digits, all defined in the Domestic Mail Manual.
A padded envelope on the Newark to Atlanta lane, quoted 2026-07-28
Small flats are exactly the pieces where barcode talk starts, so here is what one costs to move. This is a 9 x 6 x 1.5 in padded envelope at 0.6 lb, quoted through the SMKlog calculator on one day with the full board kept intact.
| Carrier | Service | Price | Quoted transit |
|---|---|---|---|
| USPS | Ground Advantage | $8.86 | 8-9 business days |
| FedEx | Ground Economy | $10.06 | 6-7 business days |
| UPS | Ground | $10.31 | 2-3 business days |
| UPS | 3 Day Select | $15.13 | 5-6 business days |
| UPS | 2nd Day Air | $15.38 | 2-3 business days |
A dollar and forty-five cents separated the postal row from UPS Ground while the estimate dropped from 8 to 9 business days down to 2 to 3, which is the sort of trade the barcode has nothing to do with. Barcodes decide routing accuracy; the service you pick decides speed and price.
Eleven digits, then bars
The Postal Service defines a delivery point code as "the finest depth of code to which a mail piece can be sorted by its address. It is usually the 11-digit numeric code formed from the ZIP+4 code and represented by the delivery point barcode (DPBC)", per the Address Information System Products Technical Guide on postalpro.usps.com, checked 2026-07-28. Nine of those digits are the ZIP and its add-on; the last two narrow it to a single point on a carrier route. Publication 28 section 226 adds the obvious requirement that a preprinted barcode must be correct for the address, city, state and code printed beside it.
The Intelligent Mail barcode swallowed it
The Domestic Mail Manual describes an Intelligent Mail barcode as one that "consists of 65 vertical bars, each representing one of four possible states: full bar, ascender, tracker, and descender", per DMM 204 at pe.usps.com, checked 2026-07-28. The Postal Service instruction sheet breaks the contents into a 20-digit tracking code field carrying the Barcode Identifier, Service Type Identifier, Mailer Identifier and Serial Number, plus a routing code field of up to eleven digits which "can contain a 5-digit ZIP Code, 9-digit ZIP+4 code, or 11-digit delivery-point code", per about.usps.com, checked 2026-07-28. Mailers may leave the routing code empty and use the barcode purely for tracking.
What a parcel carries instead
Packages use a different symbol. The manual defines the Intelligent Mail package barcode as "the USPS-developed barcode that can be read by automated parcel-processing equipment and scanning devices and consists of a data string that generally follows the GS1-128 specification", and requires it on all commercial packages. Address quality still shows up in the rules: the compliance category for address quality checks "for a timely address that validates to a unique 11-Digit DPV", with a threshold of 90, per DMM 204 at pe.usps.com, checked 2026-07-28. None of this is a knob a shipper turns. Buy a label and the right barcodes are generated with it.
Barcode questions
What is a delivery point barcode?
It is the printed bar form of the eleven-digit delivery point code, which the Postal Service calls the finest depth of code to which a mail piece can be sorted by its address. Nine digits come from the ZIP and its add-on and two more identify the individual delivery point, per postalpro.usps.com, checked 2026-07-28.
How many digits are in a delivery point code?
Eleven. The Postal Service builds it from the ZIP+4 code plus two further digits, and an Intelligent Mail barcode routing field can carry a 5-digit ZIP, a 9-digit ZIP+4 or the full 11-digit delivery point code, per about.usps.com, checked 2026-07-28.
Do shipping labels use the Intelligent Mail barcode?
Not that one. Letters and flats carry the 65-bar Intelligent Mail barcode, while packages carry the Intelligent Mail package barcode, which the Domestic Mail Manual describes as a data string generally following the GS1-128 specification and requires on all commercial packages.
Can I read anything useful off the barcode on my label?
Not really, and you do not need to. The number that matters to a shipper is the tracking number printed in plain digits beside it, which is what our tracking page accepts. The routing information encoded in the bars exists for sorting equipment rather than for people.