postage due stamp

American  

noun

1. a stamp that is affixed to mail at a post office when prepayment of postage is insufficient, to indicate the amount that must be collected from the addressee.

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postage due stamp British  

noun

1. a stamp affixed by a Post Office to a letter, parcel, etc, indicating that insufficient or no postage has been prepaid and showing the amount to be paid by the addressee on delivery

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Etymology

Origin of postage due stamp

An Americanism dating back to 1890–95