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USPS Store
store.usps.com › postal store › shipping supplies › priority mail flat rate® large box
Priority Mail Flat Rate® Large Box | USPS.com
The Priority Mail Flat Rate® Large Box is a quick, easy, and convenient way for you to ship Priority Mail® packages.
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GoShippo
goshippo.com › blog › usps-flat-rate-box-sizes-prices-how-it-works
USPS Flat Rate Boxes: Complete Size & Pricing Guide
Remember: Whether you choose flat rate envelopes for documents, small boxes for compact items, or large boxes for heavy shipments, the key is matching your package characteristics with the most economical USPS service.
Discussions

Limited size of USPS flat rate boxes
People ship rocks, metal, sand, etc in those at the flat rate and they suck!! What are you missing? The logic of the price. It's an average to make it a super simple shipping option More on reddit.com
🌐 r/USPS
13
0
November 2, 2021
Can I customize a USPS Flat Rate (Large) Box and ship it Priority Mail using weight & dimensions?
Yes, this is acceptable. I've cut down the game boxes many times without issue. However! One time when I did this, although they accepted it at the counter of my local p.o., some jackass at the p.o. on the buyer's end decided to ignore USPS rules and charge me for a large flat rate game box. I got billed the difference through eBay; my buyer wasn't asked to pay extra upon delivery. eBay took care of the charge so I didn't have to pay it (not sure if they paid USPS as a courtesy or what), but still. I chalked the incident up to a combination of: ignorant clerk + my box cutdown game being on point. I fold those sides sharp and straight, no bending or nothing. More on reddit.com
🌐 r/Flipping
18
4
August 31, 2021
USPS Priority Mail vs USPS Priority Mail Large Flat Rate Box
If you use the large flat rate box you need to pay the large flat rate price. More on reddit.com
🌐 r/Ebay
16
9
January 1, 2019
I have a few of these board game large flat rate box for priority mail, the 11.75 x 3.125 x 23.6875 inches version.
No, that service was discontinued in 2022. It now counts as just a USPS priority mail marked box, just like there's no longer a special rate for regional rate boxes either. Use postcalc.usps.com , select 'own packaging', enter the dimensions and weight and the origination and destination zip codes and you can only use the priority mail rate. More on reddit.com
🌐 r/USPS
9
0
October 26, 2023
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USPS
usps.com › ship › priority-mail.htm
Priority Mail | USPS
Pay for your package based on how much it weighs and how far it’s going (the zone). Maximum weight is 70 lbs. You’ll need to measure your package to make sure it meets the size standards.
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EasyPost
easypost.com › home › usps flat rate boxes, envelopes, & pricing
USPS Flat Rate Boxes, Envelopes, & Pricing - EasyPost
August 10, 2025 - Outside: 11 ¼” x 8 ¾” x 6″ Inside: 11″ x 8 ½” x 5 ½” · Outside: 14″ x 12″ x 3 ½” Inside: 13″ x 5⁄8” x 11 7⁄8” x 3 3⁄8“ · As you can see while these 2 boxes are both considered to be “medium sized” they are vastly different in their dimensions and are ...
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USPS
pe.usps.com › text › dmm100 › flat-rate-reference.htm
Flat Rate — Quick Reference | Postal Explorer
Weight restrictions for Priority Mail Express International Flat Rate Envelopes are 4 pounds. Weight restrictions for Priority Mail International Large and Medium Flat Rate Boxes are 20 pounds, and 4 pounds for Priority Mail International Flat Rate Envelopes and Small Flat Rate Priced Boxes.
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Stamps.com
store.stamps.com › products › priority-mail-large-flat-rate-box
Priority Mail Large Flat Rate Box 12 1/4" x 12 1/4" x 6" – Stamps.com Supplies Store
The Priority Mail Large Flat Rate Box features pre-determined rates regardless of weight (domestically) or destination, similar to our other Flat Rate products. Size: 12 1/4" x 12 1/4" x 6", USPS SKU: LARGE-FRB Quantity/Pack: 25 Maximum Order: 20 bundles of 25 Call 1-800-610-8734 for orders ...
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USPS Store
store.usps.com › postal store › shipping supplies › priority mail® large box
Priority Mail® Large Box | USPS.com
The Postal Service® has simplified your Priority Mail® shipping process, offering the easy-to-use Priority Mail® Top-Loading Large Box. This rectangular–shaped box accommodates a variety of items such as clothing, books, and hats. Just apply tape, address and ship.
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Potomac Distribution
potomacdist.com › usps-flat-rate-boxes.asp
Potomac Distribution - USPS Flat Rate Boxes
$70 to Canada $21 to Hawaii, Alaska, Puerto Rico, Guam, and APO/FPO addresses Dimensions: 12" x 12" x 5.5" or 30 cm x 30 cm x 14 cm A large flat rate box will hold these items... Dragon Shield standard size deck protectors (100 ct) - 36 packs KMC Hyper Matte standard size deck protectors (80 ...
Find elsewhere
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Parcelindustry
parcelindustry.com › print-article-925-permanent.html
Priority Mail Large Flat-Rate Box Prices
The Postal Service has launched a new box for larger shipments, giving customers three different size and shape options, all with convenient flat-rate pricing, to meet their shipping needs. The new box is 50% larger than the current flat-rate boxes. If it fits, it ships, for just $12.95 to ...
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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
USPS mailing boxes: USPS offers ... cubic feet pricing tier of Priority Mail Cubic. See a rate comparison here. Large Flat Rate Box dimensions: 12 x 12 x 5.75 inches...
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ShipStation
shipstation.com › home › usps flat rate boxes, envelopes, and prices
USPS Flat Rate Boxes, Envelopes, and Prices
2 weeks ago - If you try to use a Flat Rate box ... one-size-fits-all packaging that lets you fit as much as you can into the box as long as it’s under 70 lbs....
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Reddit
reddit.com › r/usps › limited size of usps flat rate boxes
r/USPS on Reddit: Limited size of USPS flat rate boxes
November 2, 2021 -

It seems that most large items won't be able to fit in USPS flat rate boxes, even though the advertised weight limit is 13 ounce - 70 pounds. You will seldomly be able to find items weighing over 10 lb that will be able to fit in those flat rate boxes. However, USPS will only allow you to use flat rates if you are using their flat rate boxes to ship. Am I missing something here, or is this intended?

If you use your own container to ship, the shipping fee can be anywhere from $7.95-$322.25 depending on weight and zone. And zones can make a huge difference in the shipping fee. For example, if you're shipping a 10 lb package, it can cost anywhere from $14.40 to $83.35 depending on zones. Is there any tricks I'm missing here?

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Qwintry
qwintry.global › posts › usps-flat-rate-work
How USPS Flat Rate Boxes Work, Sizes and Prices, Priority Mail vs. Flat Rate | Qwintry Global
Send Your Package: Drop off the package at your local Post Office or schedule a pickup · Current USPS Priority Mail Flat Rate sizes and prices: Flat Rate Envelope : Ideal for documents and small items up to 70 lbs.
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USPS
about.usps.com › postal-bulletin › 2008 › html › pb22226 › html › kit_004.html
Fact Sheet: Priority Mail Large Flat-Rate Box
Postal Bulletin 22226 > New Priority Mail and Express Mail Shipping Initiatives FieldInformation Kit > Fact Sheet: Priority Mail Large Flat-RateBox · Note: The APO/FPO Flat-Rate Box is intended for use only to APO/FPO addresses; however, retail employees will not refuse these boxes if presented ...
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USPS Store
store.usps.com › store › results › free-shipping-supplies › shipping-supplies › _ › N-alnx4jZ7d0v8v
Shipping Supplies | Free Shipping Supplies | USPS.com
Priority Mail Flat Rate® Side-Loading Medium Box · Single, Pack of 10 or 25 · 14-1/8"(L) x 12"(W) x 3-1/2"(H) $0.00 · Priority Mail Flat Rate® Large Box · Single, Pack of 10 or 25 · 12-1/4"(L) x 12"(W) x 6"(H) $0.00 · Small Cremated Remains Kit 1 · Set of 1 · 9-5/8"(L) x 7-3/4"(W) ...
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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 ...
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GoShippo
goshippo.com › blog › usps-priority-mail-vs-usps-flat-rate
USPS Priority Mail vs Flat Rate: Costs, Box Sizes & Which is Cheaper 2025
Flat rate medium box cost becomes worthwhile when: ... The priority mail large box cost of $24.75 retail / $19.50 commercial offers the best value for heavy items. Large flat rate box shipping cost beats standard priority mail flat rate box ...
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EBay
community.ebay.com › t5 › Shipping › USPS-Flat-Rate-Box-Size-Wrong › td-p › 34241770
USPS Flat Rate Box Size Wrong - The eBay Community
January 22, 2024 - The Flat Rate Box sizes are wrong. It saying a large Flat rate Box is 24"x12"x6" and a medium is 14"x12"x6" ... Yikes, those dimensions make no sense. USPS used to issue a Large flat rate box with dimensions about 24x12x3, but that's only about ...