What is the difference between first class mail and regular mail?

First-Class Mail® service is an affordable and easy way for your small business to send postcards, envelopes, flats and lightweight packages.

When you stick a stamp on an envelope and place it in a mailbox, you are sending something First-Class. In other words, First-Class Mail is “regular” mail.

USPS offers a wide range of services or “classes” businesses use to mail or ship to customers, including the ever-popular First-Class Mail®. Although First-Class Mail is often associated with simply mailing letters, its services go well beyond that. Businesses of all sizes count on First-Class Mail as an economical way to send postcards, letters, flats and light packages to customers both domestically and globally.

What is First-Class Mail?

First Class Mail is the most common and affordable way to send envelopes and lightweight packages. Anything you send to customers, including bills, invoices, correspondences and merchandise can be sent via First-Class, as long as your letters weigh less than 3.5 ounces. and your parcels weigh less than 13 ounces.

Many start-ups and home business use First-Class Mail to send postcards and letters. Unlike less expensive bulk-mailing services like USPS Marketing Mail, there are no minimum number of pieces, mailing permits or presorting requirements to worry about.

In fact, some types of mail must be sent through either First-Class Mail or Priority Mail, including:

  • Handwritten or typewritten material
  • Bills, invoices and credit cards
  • Personal correspondence
  • Personalized business correspondence
  • Any mailable item that is sealed or closed against inspection

What makes First-Class Mail a first-class service?

If you visit the USPS® website you’ll find the following classes of mail listed as part of their services: 

  • Priority Mail Express®
  • Priority Mail®
  • First-Class Mail
  • USPS Marketing Mail®
  • Retail Ground®
  • Media Mail®

First-Class Mail is a higher priority class than Marketing Mail, Retail Ground or Media Mail. That means USPS prioritizes the delivery speed of First-Class Mail over those services. As its name and position on the list suggests, Priority Mail services take precedence over First-Class Mail in delivery speed.

A person delivering a parcel to women

What types of First-Class services are available?

First-Class Mail

First-Class Mail service is an inexpensive and simple way to send postcards and envelopes. First-Class Mail Forever® stamps for letters and postcards never expire, even if the First-Class postage rate goes up.

  • First Class Mail service is available at your local Post Office or through an approved-shipping service like PitneyShip.
  • Postcards, letters and flats are not eligible for USPS Tracking®, though optional services like Return Receipt and Collect on Delivery provide some tracking information. Insurance is also available.
  • First-Class Mail is not eligible for refunds.

First-Class Mail International

First-Class Mail International® service is the most affordable way to send letters and lightweight packages globally. It only takes one Global Forever® stamp to send a 1 ounce. letter or postcard to your choice to over 190 countries. Like Forever stamps, Global Forever stamps never expire, even if the postage rate goes up.

First-Class Package Service

First-Class Package Service® offers some of the best rates for your lightweight parcels and packages. Retail service is available for shipments up to 13 ounces. Commercial service is available for shipments less than 16 ounces.

  • Both Retail and Commercial services are available at your local Post Office or on the USPS website.
  • USPS Tracking® is included at no charge and optional services are available for Signature Confirmation, Return Receipt, Collect on Delivery and Insurance.
  • First-Class Package Service is not eligible for refunds.

What are the weight and size restrictions for First-Class Mail?

In most cases, if your letters, flats and packages do not meet the standards listed below you will either be charged extra or may have to send them via a different mail class.

  • First-Class Mail Postcards: Minimum size is 3½ x 5 inches, maximum size is 4¼ x 6 inches and allowed thickness is 0.007 inch to 0.016 inch
  • First-Class Mail Letters: Maximum weight is 3.5 ounces, minimum size is 3½ x 5 inches, maximum size is 6⅛ x 11½ inches and allowed thickness is 0.009 x ¼ inch
  • First-Class Mail Flats (large envelopes): Maximum weight is 13 ounces, minimum size is 6⅛ x 11½ inches, maximum size is 12 x 15 inches and allowed thickness is ¼ to ¾ inch.
  • First-Class Package Service: Maximum weight is 13 ounces and maximum size is no more than108 inches in length and girth combined.

What is the delivery window for First-Class Mail?

The estimated delivery time for First-Class mail is one to three days from the postmarked date. If you’re sending something locally, your delivery might only take one day. However, First-Class Mail delivery times are estimates only and not guaranteed by USPS.

What are First-Class Mail rates?

First-Class Mail rates vary depending on what you’re sending. (A postcard is obviously less expensive to send than a package). What makes First-Class such a great deal is that those prices remain the same regardless of destination. You can find the most current First-Class Mail rates on the USPS website.

Businesses of all sizes take advantage of online shipping solutions like PitneyShip to get discounts on First-Class Stamp rates, and the savings that provides really add up.

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