GLOSSARY
Presort
By Justin Winter · Updated August 28, 2026
Sorting mail into ZIP code order, and grouping it into USPS-defined batches, before it is entered into the mail stream — required for many commercial discount rates.
Presorting groups pieces bound for the same carrier route, ZIP code, or larger geographic sortation ahead of time, so USPS equipment does less of that sorting work itself. In exchange, mailers who presort to USPS specifications and hand off mail already batched this way qualify for reduced postage rates.
It is a volume-mailing concept — a single letter has nothing to presort against — which is why it applies to commercial mail production rather than to sending one document.
See also
- Automation-compatible mail — Mail prepared to USPS specifications — correct size, a valid barcode, standardized address placement — so it can be sorted entirely by machine, which qualifies it for lower postage rates.
- PAVE certification — A USPS testing program (Presort Accuracy, Validation, and Evaluation) that certifies mailing software correctly presorts and barcodes mail to postal standards.
- Intelligent Mail barcode — The USPS barcode printed on letter mail that encodes routing and a unique piece identifier, enabling automation rates and tracking.
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