First-Class Postage

What is first-class postage?

First-class postage can be used to send all manner of documents, with standardized prices on items up to 3.5 ounces and increased pricing based on shape and weight for mailings up to 13 ounces.

To qualify for first-class postage, a mailed object must meet certain criteria. Typically, it must be rectangular, within the size and weight requirements laid out by USPS, and machinable, meaning it is not rigid, lumpy, or irregularly shaped and does not have clasps or other fixtures that might interfere with the post office’s processing machinery.

FAQs 

How much is US postage first-class?

Pricing for USPS first-class mail can change over time. As of May 2025, the cost to mail standard-sized first-class mail letters is $0.73, and postcards cost $0.56. Large envelopes or irregularly shaped first-class mail items are more expensive, typically ranging from just over a dollar to several dollars to ship.

What is the difference between 1st and 2nd-class postage?

USPS does not offer a service known as second-class postage any longer, but items formerly shipped as second-class mail are now processed as “periodicals.” These mailings typically include things like newspapers and magazines, which are given a different rate than first-class packages.

Can I mail boxes first-class?

Yes, as long as you do not use USPS packaging like priority mail boxes, and your package conforms to size and weight restrictions. For an item to be sent by first-class mail, it must be 13 ounces or less in weight and its combined length and girth must be no greater than 108 inches.