
That being said, let's dive into the different USPS Priority Mail Box and Envelope options. With a USPS Flat Rate Box or Envelope, you will be able to ship any item of any weight up to 70lbs to any location for the same price assuming it fits properly, without any bulging, within its designated box or envelope. If using non-customized boxes is not a deal breaker for you, USPS Flat Rate Shipping is a great tool to spend less on shipping. This can be a drawback for some because, unless you are a high volume shipper, you cannot get customized boxes with specific branding. 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. You can pick them up at any post office or USPS will actually ship the boxes opens in new tab open_in_new to you for free. One of the many benefits of shipping with USPS Flat Rate Boxes is that the boxes themselves are free. Sizes for parcels that weigh 13 ounces or less.How You Can Use USPS Flat Rate Boxes and Envelopes to Save on Shipping.Contact your Business Mail Entry Unit for more information. There are special size requirements for mailing flats atĬarrier route prices. USPS Marketing Mail Carrier Route flats.

"High" (the height) is the side perpendicular to the length. What is long? What is high? For flats, "long" (the length) is the side parallel to the address as read.If so, you can save money because you'll pay the lower letter price. Is it possible to fold your flat-size piece to More about Physical Standards for Commercial Flats The higher the weight the higher the postage, especially for First-Class Mail. The maximum size for a flat provides plenty of room to put lots of material in the envelope. * Large Envelopes exceed one or more of the letter size maximum dimensions. Be no more than 12 inches high x 15 inches long x ¾ inch thick.Have one dimension that is greater than 6-1/8 inches high OR 11-½ inches long OR ¼ inch thick.

The words large envelopes and flats are used interchangeably. The Postal Service uses the word "flats" to refer to large envelopes, newsletters, and magazines.
