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Index/Organizations/PostalPro

PostalPro

Fact-Checks

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Jan 31, 2026

who applies the barcode to USPS letters with IMB

The barcode known as the Intelligent Mail barcode () is generated and applied by the mailer — that is, the sender or an agent acting for the sender (for example a presort house or print vendor) — not ...

Jan 31, 2026

why don't all USPS letters have the IMb barcode printed on them

The (IMb) is a 65-bar, sender-applied code that combines routing and tracking data and can be required for or for , but its use is optional for many mailers and constrained by technical, programmatic ...