I'd advise you to not insert the flat rate boxes into a poly for shipping. The boxes are free to use for flat rate postage and to abuse their intended purpose is one thing, but it would also suck if your package was randomly inspected and charged for the flat rate instead. Sure, you will get anecdotes from people that abuse the system saying they never get caught, but all it takes is one time for a bad day with your customer. Answer from quanfused on reddit.com
USPS Store
store.usps.com › postal store › shipping supplies › priority mail flat rate® medium box
Priority Mail Flat Rate® Medium Box | USPS.com
The Priority Mail Flat Rate® Medium Box is a quick, easy, and convenient way for you to ship USPS Priority Mail® packages.
USPS
usps.com › ship › priority-mail.htm
Priority Mail | USPS
Check delivery time estimates with the USPS Service Standards Map. Priority Mail Flat Rate® products let you ship packages up to 70 lbs to any state at the same price. Ship from Post Office™ locations or online from your home or business.
USPS Medium Box 11 x 8.5 x 5.5 Equivalent Sized Side Loading Box Option?
I'd advise you to not insert the flat rate boxes into a poly for shipping. The boxes are free to use for flat rate postage and to abuse their intended purpose is one thing, but it would also suck if your package was randomly inspected and charged for the flat rate instead. Sure, you will get anecdotes from people that abuse the system saying they never get caught, but all it takes is one time for a bad day with your customer. More on reddit.com
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February 26, 2025USPS Priority Mail Medium Flat Rate Box is $16.65
I use Pirateship to ship games being sold/traded. USPS Ground is a boon if you have a box. USPS Priority Mail is cheaper than getting the label direct from USPS. More on reddit.com
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January 20, 2025When do you decide to use USPS flat rate boxes vs. Your own custom box?
Use whichever box costs the least in postage. It will vary with the size/shape/weight of the item. A flat-rate box can be anywhere from the cheapest option to the most expensive.
This site will tell you which box to use:
https://www.flippertools.com/fitShipper/
More on reddit.com 9
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March 25, 2017Getting my money's worth on a medium flat rate box.
Barely half way there to max weight. Go on, throw in some more sand.
More on reddit.com 30
76
June 20, 2014How is the flat rate determined?
The flat rate is based on three factors: packaging size, destination and the delivery speed chosen. A benefit of FedEx One Rate pricing is customers shipping shorter distances can take advantage of more economically priced options.
fedex.com
fedex.com › en-us › shipping › one-rate.html
Easy 1-, 2-, 3-Day Flat-Rate Shipping | FedEx One Rate
Does the FedEx One Rate price include cushioning or internal packing materials?
No, internal packing materials are not included in the price. If you need help, we’ll be happy to pack and ship your packages at FedEx Office for an additional fee.
fedex.com
fedex.com › en-us › shipping › one-rate.html
Easy 1-, 2-, 3-Day Flat-Rate Shipping | FedEx One Rate
How do I order complimentary FedEx One Rate Packaging for my shipping needs?
FedEx complementary packaging supplies is provided at any FedEx Office or retail location. You can complimentary order supplies online for free with a FedEx account.
fedex.com
fedex.com › en-us › shipping › one-rate.html
Easy 1-, 2-, 3-Day Flat-Rate Shipping | FedEx One Rate
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Why you shouldn't use Medium or Large Flat Rate Boxes - YouTube
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How to use USPS Regional Rate A & B Boxes! - YouTube
Stamps.com
store.stamps.com › products › priority-mail-medium-flat-rate-box
Priority Mail Medium Flat Rate Boxes, 25/pack – Stamps.com Supplies Store
The Priority Mail Medium Flat Rate Box features predetermined rates regardless of weight (domestic only). USPS SKUs: Priority Mail Medium Flat Rate Box (11 1/4" x 8 3/4" x 6"): O-FRB1 Priority Mail Medium Flat Rate Box (12" x 3 1/2" x 14"): ...
UPS
ups.com › us › en › support › shipping-support › shipping-costs-rates › flat-rate-shipping
Flat Rate Shipping | UPS - United States
With our flat rate shipping option - UPS Simple Rate - choose the appropriate packaging and speed and ship anywhere in the U.S. for a predictable, flat rate.
Stamps.com
stamps.com › wp-content › uploads › 2022 › 04 › priority-mail-box-guide.pdf pdf
USPS® Priority Mail® Box Size Guide
The table below shows options for different Priority Mail Boxes and Envelopes, along with dimensions, online postage pricing and ... Order USPS Supplies in Bulk! Call 1-800-610-8734. ... All prices listed are Commercial Base rates (effective January 2014), only available for online postage vendors such as Stamps.com. Download this PDF guide at www.stamps.com/whitepapers · Priority Mail Flat ...
Reddit
reddit.com › r/flipping › usps medium box 11 x 8.5 x 5.5 equivalent sized side loading box option?
r/Flipping on Reddit: USPS Medium Box 11 x 8.5 x 5.5 Equivalent Sized Side Loading Box Option?
February 26, 2025 -
I often reuse boxes whenever possible but the medium flat rate box from USPS is a nice size for some things I sell. Any options out there that are identical but not branded? I was thinking I could just use the USPS box and put in a giant poly bag if I can find the right size...11 x 8.5 x 5.5. My search finds some side loaded options but there are half the height...
Any known sources please let me know. Thanks!
Top answer 1 of 5
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I'd advise you to not insert the flat rate boxes into a poly for shipping. The boxes are free to use for flat rate postage and to abuse their intended purpose is one thing, but it would also suck if your package was randomly inspected and charged for the flat rate instead. Sure, you will get anecdotes from people that abuse the system saying they never get caught, but all it takes is one time for a bad day with your customer.
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Walmart carries an 11.5x7.5x5.5 for roughly 83 cents
FedEx
fedex.com › en-us › shipping › one-rate.html
Easy 1-, 2-, 3-Day Flat-Rate Shipping | FedEx One Rate
FedEx First Overnight® (Next day by 8 or 8:30 a.m.) - FedEx® Envelope: $126.35 - FedEx® Pak: $170.85 - FedEx® Small Box: $184.80 - FedEx® Medium Box: $201.95 - FedEx® Large Box: $224.35 - FedEx® Extra Large Box: $290.55 - FedEx® Tube: ...
Western Oregon University
wou.edu › mail › home › domestic-mail › united-states-postal-service-usps › usps-priority-mail › usps-priority-flat-rate
USPS Priority Flat Rate – University Mail Services
Home » Home » Domestic Mail » United States Postal Service - USPS » USPS Priority Mail » USPS Priority Flat Rate Menu
EasyPost
easypost.com › home › usps flat rate boxes, envelopes, & pricing
USPS Flat Rate Boxes, Envelopes, & Pricing - EasyPost
August 10, 2025 - As you can see while these 2 boxes are both considered to be “medium sized” they are vastly different in their dimensions and are designed to fit different types of items. Large USPS Priority Mail Flat Rate Boxes are great for larger items such as laptops, computers, gifts, and larger electronics.
GoShippo
goshippo.com › blog › usps-flat-rate-box-sizes-prices-how-it-works
USPS Flat Rate Boxes: Complete Size & Pricing Guide
Small Flat Rate Box · Dimensions: ... zones 5-9, 21-70 lbs all distances) Medium Flat Rate Box (Top-Loading) Dimensions: 11¼" x 8¾" x 6" USPS Retail Price: $18.40 ·...
Reddit
reddit.com › r/hexandcounter › usps priority mail medium flat rate box is $16.65
r/hexandcounter on Reddit: USPS Priority Mail Medium Flat Rate Box is $16.65
January 20, 2025 -
New USPS rates went into effect on 19 January, the commercial rate (what you can get using PirateShip, etc...) for USPS Priority Mail Medium Flat Rate Box is $16.65.
At least for the USPS Priority Mail Medium Flat Rate Box this does not look like a rate increase from last year.
Amazon
amazon.com › USPS-Flat-Rate-Boxes › s
Amazon.com: USPS Flat Rate Boxes
Check each product page for other buying options. Price and other details may vary based on product size and color · United States Postal Service Priority Mail Forever Prepaid Flat Rate Padded Envelope (Pack of 2) · Qilery 100 Pcs Shipping Boxes Cardboard Gift Corrugated Cardboard Brown Boxes ...
USPS Store
store.usps.com › postal store › shipping supplies › priority mail flat rate® side-loading medium box
Priority Mail Flat Rate® Side-Loading Medium Box | USPS.com
The Priority Mail Flat Rate® Side-Loading Medium Box is a quick, easy, and convenient way for you to ship Priority Mail packages.
Send Overnight Mail
sendovernightmail.com › lp › usps-flat-rate-box-shipping-cost
USPS Flat Rate Box Shipping Cost
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 ·
ShipStation
shipstation.com › home › usps flat rate boxes, envelopes, and prices
USPS Flat Rate Boxes, Envelopes, and Prices
2 weeks ago - Whereas flat rate boxes don’t have weight, dimensions, or delivery zone factored into them, standard Priority Mail parcels do. For lighter parcels, it’s usually less expensive to use your own packaging and get a rate. For example: a 3 lb package from NY to CA might cost less with a user-supplied box vs. USPS medium flat rate box price.
Pirate Ship
support.pirateship.com › en › articles › 1831802-why-you-shouldn-t-use-medium-or-large-flat-rate-boxes
Why you shouldn't use Medium or Large Flat Rate Boxes | Pirate Ship Support
If you used your own box that was the same size or even a little bigger, like 14 x 12 x 4 inches, it would be in the 0.4 cubic feet pricing tier of Priority Mail Cubic and can save you up to $8.64, depending on how far you're shipping it. See the image below to see a savings comparison between the Medium Flat Rate Box and Priority Mail Cubic:
ShipScience
shipscience.com › what-is-the-price-of-a-usps-medium-flat-rate-box
What Is the Price of a USPS Medium Flat Rate Box? - ShipScience - Helping Businesses Ship Smarter
Convenient Packing: The box's simple ... about unexpected charges. As of 2023, the USPS Medium Flat Rate Box is priced at $15.25 for non-commercial rates and $12.75 for commercial mailers....
Pirate Ship
pirateship.com › usps › priority-mail-flat-rate
Cheaper USPS Priority Mail Flat Rate | Pirate Ship
Even with Pirate Ship's Commercial Pricing shipping rates, there are only two types of Flat Rate packaging that are always a great deal: Priority Mail Flat Rate Envelopes (including Priority Mail Legal Flat Rate Envelope and Priority Mail Padded Flat Rate Envelope) and the Priority Mail Small Flat Rate Box. For other sizes, such as the Priority Mail Medium Flat Rate Box and the Priority Mail Large Flat Rate Box, you could save up to 62% by shipping your items with Priority Mail Cubic® in your own comparably-sized packaging instead.
Onyxproducts
onyxproducts.com › collections › priority-mail-boxes-1
Priority Mail Boxes
ONYX Products™ is your new premium shipping supplies source. We are a proud partner of Stamps.com, ShipStation, Endicia, ShipWorks, and Shipping Easy and offer everything from postage & shipping scales, to thermal printers, shipping labels, boxes, tape, bubble mailers and more!
US Global Mail
usglobalmail.com › blog › medium-flat-rate-box-price
Medium Flat Rate Box Price - US Global Mail
September 30, 2022 - A Medium Flat Rate Box is a box that can be used to ship items via USPS’s flat rate service. The flat rate service allows you to send mail to any part of the US for one cost, regardless of how much the package weighs. Flat Rate is often used when sending heavy items over a long distance, because it is cheaper than paying according to the weight and the zone.