---
title: "Can I use Flat Rate packaging with other USPS services?"
url: "https://www.shipstation.com/faq/can-i-use-flat-rate-packaging-with-other-usps-services/"
type: "faq"
modified: "2026-06-10T09:39:04-05:00"
---
No. Priority Mail Flat Rate packaging is designed for Priority Mail service. If you try to apply it to a different service, you may run into rating or label errors. ShipStation helps by keeping package choices tied to the correct service.