What is included in the definition of “mailable items” under First Class Mail?

The definition of "mailable items" under First Class Mail includes items weighing less than 13 ounces. This category encompasses letters, postcards, and small parcels that meet the criteria established by USPS regulations. First Class Mail is designed to provide reliable delivery at an affordable cost for items that can be easily handled and sorted, which is why there is a weight limitation of 13 ounces. This weight restriction ensures that the items remain within a range that allows for efficient processing.

Larger items, such as those weighing 16 ounces or more, typically fall into different mailing categories, such as Priority Mail. The classification of mailable items also extends beyond just letters and envelopes to include various types of packages that meet the specific weight and dimensional requirements set forth by USPS. Therefore, understanding that only items under 13 ounces are considered mailable under First Class Mail is crucial for anyone preparing or processing mail in this category.