Choosing the Right USPS Mail Class

Learn about the different USPS mail classes and how to choose the right one for your business
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When you’re ready to ship your package with USPS, you’ll have to choose which mail class to ship it in. However, choosing which USPS mail class makes the most sense for you isn’t as simple as Eenie, Meenie, Miney, Moe. There are a number of variables that affect which mail class you should choose, but we’re here to help you figure it out. Let’s dive in!

Table of Contents

What is a Mail Class?

Let’s start with a simple definition. Mail Classes describe the different mailing and shipping services that USPS provides to customers. Each mail class varies when it comes to cost, the time it takes for a package to be delivered, the items allowed in the package, and the maximum weight allowed. USPS offers several different mail classes, both for domestic and international shipments. We’ve listed them out for you below.

Domestic Mail Classes

  • Priority Mail
  • Priority Mail Express
  • First-Class Mail
  • First-Class Package
  • USPS Media Mail
  • USPS Retail Ground/Parcel Select Ground

International Mail Classes

  • First Class Package International
  • Priority Mail International
  • Priority Mail Express International

Pro Tip: Don’t let the term “Mail Classes” fool you! Remember that USPS offers both mailing and shipping services within the different mail classes. Mailing implies sending letters, while shipping implies sending parcels and packages.

Domestic USPS Mail Classes

Priority Mail

The shipping service that USPS advertises the most, Priority Mail is the cheapest way to ship small packages. Priority Mail boasts three distinct standards: free package tracking, delivery occurring between 1-3 days, and $100 of built-in insurance. You can ship any box or envelope with Priority Mail, and you can actually use any type of packaging!

With the best mix of fast delivery speeds and low cost, there are four sub-services of Priority Mail to help you maximum your savings when shipping USPS. All Priority Mail sub-services have the same standards as Priority Mail. We’ve listed each sub-service below for you to check out.

Priority Mail Express

Priority Mail Express is the fastest delivery service that USPS offers, with overnight delivery in most cases. However, it’s important to note that this mail class is only overnight to and from urban areas—rural areas take 2 days. While more expensive than the other mail classes, packages are guaranteed to be delivered on time, or else you’ll get a full refund. Like all other Priority Mail services, Priority Mail Express Service includes free package tracking and automatically comes with $100 of built-in insurance.

First-Class Mail

If you’re sending lightweight items like postcards, letters, and large envelopes that weigh less than 3.5 ounces, you’ll likely be sending them First-Class Mail. This service is typically used for personal correspondence, business correspondence, and that B-word we all hate the most…bills.

First Class Package

First Class Package Service is the cheapest way to send small packages that weigh up 15.9 ounces. Like Priority Mail, First-Class Package is delivered within 1-3 business days to anywhere in the United States. The price of First-Class Package postage is set by the total weight along with the USPS zone the package is being shipped to.

USPS only offers two pricing levels for First Class Package: Retail and Commercial. When you use shipping software to get Commercial Pricing rates, you can save up to 28% more on First-Class Package than what you’d pay at the Retail rate.

USPS Media Mail

If your package only contains books, videos, vinyl records, or purely educational material, USPS Media Mail is hands down the cheapest shipping service. Free package tracking is included, and delivery usually occurs between 2-8 days. The maximum weight for individual packages sent with Media Mail is 70 pounds, and the price of postage is based on the total weight of the package. Keep in mind, USPS can be quite strict about how Media Mail is used. No other merchandise or advertising material is allowed inside your box and USPS may inspect your packages to ensure compliance.

USPS Retail Ground/Parcel Select Ground

USPS Retail Ground is the cheapest way to send large packages up to 70 pounds with USPS. That being said, it’s also the slowest option. Delivery can occur anywhere between 2-8 days, depending on where you’re shipping your package to. Retail Ground is really only a good option for sending very large boxes, or for packages with hazardous ORM-D materials that have to be transported by ground only. Such materials include aerosols, certain beauty products, ammunition, and more. All that being said, if your packages don’t contain ORM-D materials, Retail Ground isn’t your best option.

Pro Tip: If you sign up for online shipping software that lets you access Commercial Pricing rates, Retail Ground gets upgraded to a service called USPS Parcel Select Ground. The two services are exactly the same; the only difference is you’ll save up to 41% more than if you use Retail Ground.

International USPS Mail Classes

First Class Package International

First Class Package International is the cheapest international shipping service USPS has to offer for packages lighter than 4 pounds. Delivery takes 1 to 3 weeks (depending on the destination), and it includes free package tracking to 41 major countries. However, First-Class Package International DOES NOT include built-in insurance. Therefore, it’s critical to purchase shipping insurance (article link: Basics of Shipping Insurance) for anything you’re sending First-Class Package International. You can do so through USPS or a third-party insurance provider (which is usually available as an add-on through your shipping software solution).

Pro Tip: On Pirate Ship’s Shipping Software, First-Class Package International passes through Commercial Pricing to to hook you up with the deepest discounts on international postage. Pirate Ship also offers Simple Export Rate, a special pricing tier that technically gets the same service as First-Class Package International, but gives you EVEN more savings and simplified pricing. You can create an account for free and save up to 40% more with Simple Export Rate compared to all other services!

Priority Mail International

If your package weighs more than 4 pounds, Priority Mail International will be your cheapest option to ship internationally with USPS. Depending on the destination, delivery occurs between 6 to 10 business days. Priority Mail International comes with free package tracking to any destination, and also includes $200 of built-in insurance.

Priority Mail Express International

If your package needs to be delivered lickety-split, Priority Mail Express International is the way to go. Simply put, this is the fastest international service USPS has to offer. With delivery occurring within 3 to 5 business days (depending the country you’re shipping to), this mail class also includes $200 of built-in insurance and free package tracking.

Priority Mail Cubic

Now that we’ve gone over those different mail classes, let’s get to the good stuff. E-commerce business owners, PAY ATTENTION, because your life is about to change! Let’s talk more about one of the four sub-services of Priority Mail: Priority Mail Cubic.

Like all Priority Mail services (and sub-services), Priority Mail Cubic delivery occurs between 1-3 business days, includes package tracking, and comes with $100 of insurance. However, this particular mail class has some restrictions your package must meet. We’ve outlined those below:

  • No dimension can be more than 18 inches
  • Total weight can’t be more than 20 pounds
  • Total volume can’t be more than 0.5 cubic feet

Why Ship Priority Mail Cubic?

If your small business ships out a lot of packages, you know that postage adds up fast—even at Commercial Rates. Fortunately, Priority Mail Cubic is the answer to all your prayers!

We’ll break it down for you as simple as possible. Priority Mail Cubic is the cheapest AND fastest way to ship small parcels between 1 and 20 pounds. To speak frankly, it’s one of the cheapest ways to ship with USPS. Unlike the other mail classes, Priority Mail Cubic isn’t priced based on weight. Instead, price is determined by the outer dimensions of your package. That means you can load those suckers up with as many items as you can fit, just as long as the total weight doesn’t exceed 20 pounds.

Pro Tip: We bet you didn’t know that you can get free USPS boxes that can be used for Priority Mail Cubic! You’re welcome.

So…How Can I Ship Priority Mail Cubic?

Houston, we have a problem. Even though Priority Mail Cubic is the best way to save money on shipping small packages, you can’t exactly ask for it at the Post Office. Typically, the only way to ship Priority Mail Cubic is to enter into a direct contract with USPS. Those contracts have specific requirements, such as shipping over 50,000 parcels per year. Realistically, that’s a tough mark for a lot of small businesses to hit!

Don’t get discouraged though, because we’ve got good news! There’s actually free USPS shipping software out there that lets you ship Priority Mail Cubic without ANY contracts or fees. It’s easy to create a free account and immediately get access to USPS discounts that businesses shipping at least 50,000 packages a year get. That means YOU get hooked up with the deepest discounts possible, so you save money that you can reinvest back into your small business! Pretty cool, right?

Looking for the right shipping software for you?

To get the deepest discounts and the most USPS mail classes, check out our guide:

Choose the Best Shipping Software

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