PayPal Shipping Center supports the USPS Large Envelope/Flats package type for International and Domestic Shipments.
This package type has very specific requirements which can result in an adjustment in rates for upgrading to a different service if the requirements are not followed.
When shipping with USPS it is imperative to always make sure you are aware of the size of your packages. If you are unsure of the size of your mail, there are tools you can use like the USPS guide that shows you how to measure properly.
USPS First-Class Large Envelope/Flats is the best way to ship documents and other flat material like pamphlets you do not want to fold or CDs.
USPS uses the word "flats" to refer to large envelopes, newsletters, and magazines. The words "large envelopes" and "flats" are used interchangeably.
For your mail to be considered a large envelope/flat and not a letter, it must exceed one or more of the letter-size minimum dimensions listed below.
Minimum Size: 11-1/2"(L) x 6-1/8" (H) x 1/4" (thickness)
For your mail to be considered a large envelope/flat and not a package (parcel), it must not exceed the following criteria:
Maximum Size: 15" (L) x 12" (H) x 3/4" (thickness)
Maximum Package Weight
The maximum weight for large envelopes is 13 ounces. Large envelope/Flats can be shipped via First Class or Priority Mail, however, a large envelope/flat exceeding 13 ounces is classified as a Priority Mail item.
Tracking Not Available for Large Envelopes/Flats
Large Envelopes/Flats shipped via First-Class Mail are not eligible for tracking and will not include a barcode on the label.
Tracking is included when shipping via Priority Mail or when using a custom package type with First-Class Mail.