Prices start at $10.45 at a Post Office. (Ship online with Click-N-Ship® and get lower Commercial Rates. Businesses can get additional savings by opting in to the Business Rate Card .)

Tracking and insurance are included, ... Priority Mail postage and shipping labels at a Post Office or online. Prices start at $10.45 at a Post Office....

The Priority Mail Flat Rate® Medium Box features predetermined rates regardless of weight (domestically) or destination, similar to the Flat Rate Envelope. Please Note: This item ships in singles, and packs of 10 or 25 boxes.

October 23, 2025 - One of the many benefits of shipping with USPS Flat Rate Boxes is that the boxes themselves are free. You can pick them up at any post office or USPS will actually ship the boxes to you for free. In order to have access to the USPS Priority Mail Flat Rate pricing, you must use one of USPS designated Flat Rate Boxes; you cannot use just any box of the same dimensions.

This "if it fits, it ships" approach makes flat rate boxes ideal for heavy items traveling long distances. ... To use Priority Mail flat rate service, you must use official USPS flat rate branded boxes and envelopes. Regular Priority Mail boxes won't qualify for flat rate pricing. ... Here are the current USPS flat rate boxes prices and sizes, along with Shippo's discounted commercial rates (accurate as of 2025):

It features predetermined rates regardless of weight (domestically) or destination, similar to our other Flat Rate products. This item ships in singles, and packs of 10 or 25 boxes.

October 9, 2025 - Save money with Priority Mail Flat Rate. Pay one flat rate to ship up to 70 lbs. with the U.S. Postal Service.

December 2, 2025 - USPS medium flat rate box price. USPS also offers Flat Rate International options through Priority Mail International and Priority Mail Express International. These let you send packages to over 180 countries with tracking and up to $200 insurance. Tip: Use ShipStation’s multi-carrier tools to automate customs documentation and compare international flat rate options from USPS and other carriers.

If It Fits, It Ships®. Priority Mail® service offers a variety of Flat-Rate Boxes and Envelopes that ship for the same price to any domestic address, regardless of how much they weigh or how far they’re going. Prices vary by product, as shown in the table below.

USPS postage rates offer low-cost mailing and shipping prices for domestic & international customers. See Forever postage stamp prices and other postage rates.

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Shop our selection of Free Shipping Supplies Shipping Supplies on the USPS.com Postal Store

Large flat rate box shipping cost beats standard priority mail flat rate box prices when: ... Priority mail envelope rate for standard envelopes starts around $8.15, while USPS priority envelope cost for flat rate versions is $9.85.

May 20, 2021 - Flat rate shipping means the price of shipping is not connected to the weight, shape, or size of the shipped item, hence the term “flat rate.” It’s based on how much you can stuff into the USPS-issued box.

Flat Rate · Prepaid · ReadyPost · Cremated Remains · Cold Chain · Filter products by the available quantities. Single (12) 2 to 10 (16) 11 to 20 (1) 21 and Above (13) Filter products based on price ranges. $0 only (19) $11 to $20 (1) $21 to $50 (4) Priority Mail Shipping Supplies Boxes ·

July 25, 2025 - USPS flat rate shipping® is a service that allows businesses to ship packages at a fixed rate, regardless of the package's weight (up to 70 lbs) or destination—so long as it fits within an approved USPS flat rate box or envelope. This simplicity is what makes it a go-to for many ecommerce businesses. Instead of dealing with fluctuating shipping prices, zone charts, or weight-based rates, businesses can simply pick the right-sized box or envelope and pay one flat fee.

July 25, 2023 - USPS Flat Rate Shipping offers ... are its main features: Fixed Price: The shipping cost stays the same for all domestic destinations, as long as the package weighs 70 lbs or less....

And like all USPS flat rate boxes and envelopes, the box is available free of charge and also can be used for international shipping.

What's the USPS Flat Rate Box Shipping Cost? Get these details and more with SendOvernightMail.com, the easiest and fastest way to send documents, letters, and forms online · Upload Your Letter Upload Letter · Pricing FAQ · Contact Us Terms of Service Privacy Policy Security ·