Ever looked at a USPS package and seen a long line of numbers? That’s a tracking number, USPS tracking numbers are not just random. 

They have a special order that tells us about the package, like where it’s going and how it’s being sent. We’ll explain these numbers so you can understand them easily.

Knowing what your tracking number means is really helpful, especially if you send or get a lot of packages. 

In this article, we’ll make it easy to learn about these numbers. Stick with us to find out more about how USPS keeps track of packages with these numbers.

Key Takeaways:

  • USPS tracking numbers are unique codes, varying in length, used to track the location and status of your shipments.
  • Domestic USPS tracking numbers typically contain 20 – 22 digits, while international numbers are alpha-numeric.
  • The tracking number can be easily found on the USPS receipt, usually located at the top.
  • Tracking a USPS package is accessible online, via the mobile app, text, or phone call, providing real-time shipment updates.

What Is USPS Tracking Number?

A USPS tracking number is a unique code assigned to every package which allows you to track the location and delivery status of your package.

These tracking numbers come in different lengths and formats, typically ranging from 20 to 22 digits for domestic mail. 

For international shipments, the format often includes both letters and numbers. The structure of a tracking number provides crucial information about the shipping method and package type. 

For instance, a number starting with “9400” indicates standard USPS tracking, while “9270” signifies Priority Mail Express.

What Does A USPS Tracking Number Look Like?

Let’s understand the appearance of a USPS tracking number. These numbers are more than just a string of digits; they’re a key to understanding the journey of your package. 

Each USPS tracking number has a distinct format, showing the service type and mail class.

A typical USPS tracking number for domestic mail is a series of 20 to 22 digits. For example, a standard tracking number looks like “9400 1000 0000 0000 0000 00”. 

The numbers are not random; they provide specific information about the shipment. The first few digits indicate the type of service used, such as Priority Mail or Certified Mail.

For international shipments, the format includes both letters and numbers. For instance, Priority Mail tracking numbers might appear as “CP 000 000 000 US”. 

This format usually starts with two letters, followed by nine digits, and ends with “US”.

USPS Tracking Number Format: Service Wise

Now, let’s understand the specific formats of USPS tracking numbers, categorized by service. These formats play a crucial role in identifying the type of service used for shipping your package.

All Numbers

For most domestic services, USPS tracking numbers are composed entirely of numbers, typically 20 to 22 digits long. 

This format is straightforward and numeric, providing a clear and easy-to-follow method for tracking. 

For example, a standard United States postal service tracking number might appear as “9400 1000 0000 0000 0000 00”.

Each set of numbers has its own significance in terms of identifying the specific mail service and tracking the package’s status.


When it comes to international shipping, USPS utilizes an alpha-numeric format. This includes a combination of letters and numbers, giving a clear indication that the package is being sent overseas. 

A common example is the Priority Mail International format, “CP 000 000 000 US”, which starts with two letters, followed by nine digits, and ends with ‘US’. 

This format not only helps in tracking but also identifies the package as an international shipment.

Formats of tracking number

Here’s a list of what these tracking numbers typically look like for different USPS services:

  • Priority Mail Express: 9270 1000 0000 0000 0000 00
  • USPS Tracking: 9400 1000 0000 0000 0000 00
  • Certified Mail: 9589 0000 0000 0000 0000 00
  • Collect on Delivery: 9303 3000 0000 0000 0000 00
  • Signature Confirmation: 9202 1000 0000 0000 0000 00
  • Registered Mail: 9208 8000 0000 0000 0000 00
  • Priority Mail: 9205 5000 0000 0000 0000 00
  • Priority Mail International: CP 000 000 000 US
  • Global Express Guaranteed: 82 000 000 00

What do international USPS tracking numbers look like?

International USPS tracking numbers are typically alpha-numeric, meaning they include both letters and numbers. 

This format helps to easily differentiate international shipments from domestic ones. A common example is the Priority Mail International tracking number, which appears as “CP 000 000 000 US”. 

This format usually begins with two letters, followed by a series of nine numbers, and ends with the letters “US”.

These alpha-numeric codes not only assist in tracking the package across different countries but also indicate the type of international service used. 

For instance, “EC” at the beginning of a tracking number would be associated with Priority Mail Express International, a service offering faster international delivery.

How Many Numbers Does It Have?

International tracking numbers usually adopt an alpha-numeric format. These tracking numbers often comprise a combination of 13 characters. 

This format generally starts with two letters (indicating the type of international service), followed by nine digits, and then ends with “US” (denoting the United States).

Where Is the Tracking Number on USPS Receipt?

When you ship a package with USPS and receive a receipt, the tracking number is typically printed on this document. 

On the receipt, you’ll usually find the tracking number near the top, just above the destination address and the postage cost. It can also be near the peel-off portion of your usps receipt.

It’s clearly labeled, often with the words “Tracking #” or “Label #”, making it easy to identify. This number is a series of digits, and its length and format depend on the type of service used for shipping.

You will also receive the tracking info in the mail sent by USPS or the retailer from whom you ordered.

How Do I Access USPS Tracking Information?

Once you have your tracking number, there are several convenient ways to access your shipment’s progress:


The most straightforward method is to visit the USPS website. Here, you’ll find a tracking section where you can enter your tracking number. 

This will give you real-time updates on your package’s location and estimated delivery time.

USPS Mobile App: 

If you prefer using your smartphone, the USPS Mobile app is a handy tool. Available for both iOS and Android, the app allows you to enter your tracking number and receive updates while on the go.

Text Updates: 

For quick updates, you can also opt-in for text tracking by sending your tracking number to 28777 (2USPS). Keep in mind that standard message and data rates may apply.


If you’re not able to access the internet or prefer speaking to someone, you can call USPS customer service. They can provide tracking information over the phone.

Informed Delivery: 

USPS also offers a service called Informed Delivery. This free feature provides digital previews of your incoming mail and can include tracking updates for packages.


What do all the USPS tracking numbers start with?

USPS tracking numbers typically start with a 9, but they can also start with an E or a C.

What USPS service has the longest tracking number?

The USPS service with the longest tracking number is First Class Package Service International, which has a 22-digit tracking number.

What is the format of a USPS tracking number?

The format of a USPS tracking number varies depending on the shipping service. However, most USPS tracking numbers are 20 digits long and consist of a combination of numbers and letters.

Does USPS have 26 digit tracking numbers?

No, USPS does not have 26-digit tracking numbers.

Can a USPS tracking number be 30 digits?

No, a USPS tracking number cannot be 30 digits. The longest USPS tracking number is 22 digits long.


Understanding USPS tracking numbers is simpler than it might seem. These numbers, varying in length and format, are essential for tracking your packages. 

Domestic shipments usually have 20 to 22-digit numbers, while international shipments have alpha-numeric codes.

Finding your tracking number is easy – just check your USPS receipt. It’s usually at the top, clearly marked. 

Once you have this number, tracking your package is straightforward. You can use the USPS website, their mobile app, text updates, or even call customer service. 

Each method offers real-time updates on your shipment’s status.

So, whether you’re sending a local parcel or an international package, USPS tracking numbers provide a reliable way to monitor your shipment’s journey. 

Alexandra Navara

Alexandra Navara is a seasoned logistics expert with over 7 years of industry experience. Holding a degree in Logistics and Supply Chain Management, she excels in writing insightful, engaging content on courier services. Certified as a Supply Chain Professional, Alexandra brings depth and clarity to complex logistics topics.

Find me here:

Leave a Reply

Your email address will not be published. Required fields are marked *