USPS Priority Mail vs. USPS First Class Mail (Detailed Difference)

USPS is the United States Postal Service, which provides a variety of shipping options for important items. Even though there are different ways to ship the parcels, people found the two most reliable. The first is priority mail, and the second is first-class mail.

Making the proper decision at the appropriate time helps save overspending and service disruptions when shipping. Therefore, selecting the one that sends your parcel on time is important.

Priority mail often ships more quickly than first-class packages, taking only 1–3 business days as opposed to 1–5 days. Larger packages can be sent via Priority Mail (up to 60-70 lbs for some services).

Don’t stress yourself out if you can’t decide between two options. We can assist you in choosing between first-class and priority mail. In this article, we will share all the pertinent information about the services mentioned, such as their cost and time frame for delivery.

Let’s get started!

What is USPS? What are Its Two Famous Services?

The United States Postal Service is a popular courier choice of e-commerce merchants because they have several domestic and international shipping options. USPS First Class and USPS Priority Mail are the two mailing options from the United States Postal Service.

Despite being famous, people don’t seem to know when they used these services or the differences between them. So today’s article will explain the difference between these two services.

First, we will look at USPS First Class and USPS Priority Mail; then, we will tell you when to choose either of these services. After that, we will discuss the further differences between these two.

USPS First Class Mail

USPS First Class Mail limits lightweight items, such as letters and padded envelopes, to under 13 ounces. The parcel should be flat and rectangular. If the package is in another shape other than a rectangle, an extra fee would be charged.

It is the most suitable and economical option for sending letters and envelopes that weigh under 13 ounces. It usually takes 1 to 3 business days to deliver the parcel. However, first-class mail has priority over other mail but is not delivered on Sunday.

USPS first-class mail service
USPS First-class Mail Service

USPS Priority Mail

USPS Priority Mail is one of the most popular options offered by the United States Postal Service. It is an extensive choice for most e-commerce merchants who want to send their parcels faster and safely.

Packages that weigh less than 70 lbs. can be transmitted through the USPS Priority Mail service. It has many benefits, like insurance coverage in case of lost or delayed items.

It has no restrictions regarding a parcel as long as it’s under 70 lbs. It can be delivered efficiently. This includes improved tracking for priority service.

When to Use USPS First Class Mail?

There are factors like the cost, size, and weight of your package, the shipping destination, and the time of delivery to consider. USPS First Class Mail is the most cost-effective option for e-commerce merchants if they want to ship items weighing under 1 pound.

  • This service can deliver letters, postcards, and large and small parcels weighing under 13 ounces. Parcels under 1 pound can also be shipped via USPS First-Class Package Service on either a retail or commercial basis. 
  • For example, if you are an e-commerce merchant selling customized t-shirts that weigh 6 ounces, you can use USPS first-class mail service as long as its packaging is rectangular.

When to Use USPS Priority Mail?

You should choose the USPS Priority Mail service to deliver your package quickly and to be prioritized on the other mail.

Of course, it would cost more than first-class mail, but it comes with a bunch of extra features that make it worth spending that money. It comes with an insurance and tracking feature.

You can ship any item under 70 lbs. with USPS Priority Mail service.

USPS priority mail service
USPS Priority Mail Service

Features of USPS First Class Mail vs. USPS Priority Mail Service

Let’s discuss the different features of the two services below.


Although the United States Postal Service is constantly changing its prints, there is a noticeable price difference between USPS First Class Mail and USPS Priority Mail service for self-evident reasons.

USPS First Class Mail is more cost-effective than USPS Priority Mail service. Its price starts at 4.80$. While USPS Priority Mail comes with a bunch of extra features and a faster delivery rate, its prices start at 9$.

Delivery Time

Although first-class mail has priority over second, third, and fourth-class mail, it still takes 1-5 business days to deliver it can be more delayed than that based on when you ship it because first-class mail does not deliver on Sundays.

While USPS priority mail can take 1-3 business days to deliver, it also delivers on Sundays. Remember that it also depends on the distance between your shipping address and where you want it shipped.


The weight limit for both options is very different. USPS First Class Mail allows a weight limit of 13 ounces; anything under that which is adequately packaged(padded envelope) can be delivered.

In comparison, USPS Priority Mail service has a weight limit of 70 lbs. It does cost extra if it weighs more than that. With Priority Mail flat rate box, you don’t have to weigh anything under 70lbs.


Let’s take a look at the USPS sizing chart since package size and dimensions are some of the most crucial factors when choosing which USPS postal service to use.

First-class mail parcels are limited to having a combined length and girth of 108″, where “length” refers to the size of the longest side and “girth” to the circumference of the thickest part of the box.

First-class mail can only transport packages up to a maximum weight of 15.99 oz. Priority mail packages can now again have a maximum combined length and breadth of 108″, but their entire weight is much higher at 70 lbs.


The built-in insurance that provides compensation for items lost or damaged during transit probably sets priority mail apart from first-class mail.

First-class mail doesn’t come with default insurance, unlike priority mail. Priority mail provides up to $100 in domestic coverage and $200 in default insurance for packages outside the United States. Fortunately, you can get extra protection from USPS or other service providers.


First-class and priority mail provide tracking updates until the shipments reach their destination, unlike insurance. It covers the day and hour of delivery and any further attempts if a delivery is missed.

Free tracking services are offered for both shipment choices. When contrasting USPS’s first-class package with priority mail, it’s important to take into account additional shipping features like the availability of a money-back guarantee, weekend deliveries, signature services, certified mail, the price of return receipts, special handling, and mailing certificates.

Weekend Delivery

USPS First Class mail does not deliver on Sundays, but it does deliver on Saturdays. On the other hand, USPS Priority Mail also delivers on Sundays.


USPS Priority Mail Service includes free shipping boxes and envelopes, while USPS First Class Mail does not come with free packaging.

United States Post Office
United States Post Office

Differences Between USPS First Class And USPS Priority Mail

To sum up the difference between USPS First Class Mail Service and USPS Priority Mail Service, let us take a look at the table below:

 FeaturesUSPS First ClassUSPS Priority Mail
Delivery time1-5 days1-3 days
Weight13 ounces70lbs
InsuranceNot includedIncluded
Weekend DeliveryNoYes
Free PackagingNot ProvidedProvided
Difference Between USPS First Class and Priority Mail

Hopefully, this table has helped you gain a quick overview of the difference between USPS First Class and USPS Priority Mail Service.

First Class Mail Vs. Priority Mail


  • Understand the differences between USPS Priority Mail and USPS First Class Mail for informed shipping choices.
  • Priority Mail delivers faster, 1-3 business days vs. 1-5 days for First Class Mail.
  • First Class Mail is for lightweight items (<13 oz), while Priority Mail handles packages up to 70 lbs.
  • First Class Mail is cheaper, starting at $4.80, while Priority Mail starts at $9.
  • Priority Mail offers insurance and better tracking, ideal for urgent or valuable items.
  • Priority Mail delivers on Sundays, unlike First Class Mail.
  • Priority Mail provides free packaging; First Class Mail does not.
  • Consider cost, delivery time, package size, and features to choose the best USPS service.

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