How to Ship to a PO Box

The history of PO boxes in the United States dates back to the 1850s when the first small letter boxes were installed on lampposts and buildings in cities.

Interestingly, the charm of PO boxes continues to be a viable part of the national mailing system. 

PO boxes, or Post Office boxes, are lockable boxes with a unique address available for rent at a local post office. People use P.O. boxes to receive mail away from home for privacy or convenience. If you are a nomad, then PO Boxes work great as you can just as easily pick up your package from the nearest post office! 

However, it is important to note that not all package sizes are welcome if you are shipping to a PO Box.  

With new shipping rules, one is forced to ask how can one send packages to these PO Boxes? What are the limitations of this process and which shipping services cater to this requirement?

We answer all these questions and more in this blog.

Understanding Post Office Boxes

Post office boxes, commonly known as PO boxes, are lockable boxes with a unique address available for rent at your local post office. These boxes provide an added layer of privacy and convenience for customers who may not have access to traditional mailboxes or prefer not to receive mail at their home address. PO boxes are especially useful for individuals who travel frequently or live in areas without reliable mail delivery. By renting a PO box at your nearest USPS location, you can ensure that your mail is secure and accessible whenever you need it.

Read More: Learn how to schedule pick ups for your USPS delivery

Steps to Ship to PO Boxes

The critical difference between shipping to a residential address versus a PO box is that you’ll insert the PO box number in place of the regular street address.

Let’s break down the process into several easy steps. First, write the name and address of the letter or package visibly. It is important to use a pen or permanent marker for clarity. Ensure you have the recipient’s address and name correctly. Clearly writing the recipient's address helps avoid mishandling. Additionally, include a return address in the upper-left corner to ensure the mail can be returned if undeliverable.

Step 1. Start at the center of the envelope

It’s essential to write the name and address of the letter or package visibly. Using a pen or permanent marker is crucial for writing the recipient's address to maintain clarity and professionalism, ensuring the ink is dark-colored for better visibility. Failing to write the recipient’s address and name correctly can result in a mishandled letter or package. Or, you may face further delays.

Step 2. Write the recipient’s first and last name on the first line

Make sure to write the recipient’s first and last name. Clearly writing the recipient's address is crucial to avoid mishandling. Though optional, you can add the recipient’s middle initial or name to ensure the wrong recipient won’t intercept it.

If the recipient goes by a formal title (i.e., Dr. Jane Doe), be sure to include it. Being as specific as possible is always the best way to ensure there won’t be issues with shipping to a PO box.

Step 3. Note the company or organization (optional)

If you’re sending mail or packages to a business address, it’s essential to include the company or organization’s name directly under the recipient’s name. This step, while optional, helps ensure that your mail reaches the correct recipient within the organization. Make sure to write the company or organization’s name in capital letters to enhance readability and avoid any potential confusion. For example:

Dr. Jane Doe ACME INNOVATIONS INC. PO Box 12345 New York, NY 10001

Step  3. Note the company or organization (optional)

This step only applies if you’re writing to an organization or company representative. The company or organization’s name goes directly under the recipient’s name.

At this point in the process, your address should look something like the following:

Dr. Jane Doe

ACME Innovations Inc.

Step 4. Provide PO box number

The recipient’s PO box number, and any PO box in general, begin with the words “PO Box,” followed by a 2-5 digit number.

USPS requests senders leave out all punctuation when addressing a letter or package for a PO box. Your address should look something like the following:

Dr. Jane Doe

ACME Innovations Inc.

PO Box 12345

Step 5. Add city, state, and postal code to the bottom line

Finally, you’re at the last step of addressing a letter or package for a PO box. This section is where you’ll specify the city and state or province. Make sure you separate the city and state with a comma.

Now, the address should look something like the following:

Dr. Jane Doe

ACME Innovations Inc.

PO Box 12345

New York, NY 10001

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✅ DO: Use "PO Box" followed by the box number.

🚫 DON’T: Include a street address (it may cause delivery issues).

Step 6. Use Easyship’s address validation for accuracy

Leverage Easyship's address validation feature to ensure that addresses passed over by your end customers are always accurate. Automatically check they are compatible with the delivery networks of carriers that support P.O. Box delivery, like FedEx SmartPost and USPS. This essential step helps prevent shipping delays and returned packages due to incorrect or incomplete addresses.

Shipping to PO Boxes with Carriers

Shipping to PO boxes can be a bit tricky, but several carriers offer services that cater to PO box deliveries. USPS is the primary carrier that ships to PO boxes, ensuring reliable and consistent service. Additionally, FedEx Ground Economy is an option, as it utilizes USPS for the final leg of delivery. 

When shipping to a PO box, it’s crucial to use the correct PO box address format, which includes the recipient’s name, PO box number, city, state, and zip code. To determine the estimated cost of shipping to a PO box, you can use a postage calculator, which helps you find the most cost-effective shipping solution.

Special Handling Requirements

When shipping to a PO box, there are special handling requirements to keep in mind. For instance, packages are only held for up to 10 business days at the USPS location. While customers may have access to their mailbox 24/7, they must wait to pick up packages during the post office’s business hours. 

Additionally, PO boxes have size and weight restrictions, so it’s essential to check with the carrier before shipping a package to ensure it meets these requirements. Being aware of these special handling requirements can help you avoid any potential issues or delays in delivery.

Shipping to Other Specialty Addresses

PO boxes aren’t the only unique addresses that require careful formatting. If you ship to these locations, follow the additional guidelines:

1. Shipping to Apartments

Include the apartment number on a separate address line:

Clark Kent  

456 Superhero Lane, Apt 190  

Metropolis, TX 12345 

2. Shipping to Military Bases

Military mail follows a specific format, requiring APO, FPO, or DPO designations:

MSgt John Doe  

PSC 123 Box 987  

APO AP 96601-0098

➡ Tip: Military addresses also require customs forms for international shipping.

3. Shipping to College Mailrooms

Campus mailboxes often use C/M or box numbers, so confirm with students before shipping:

Sidney Prescott  

996 Loomis Drive, C/M 703  

Woodsboro, CA 12345 

The Restrictions on Shipping to PO Boxes

Shipping to PO boxes can be a pain. USPS is the only carrier that can ship to PO boxes. Plus, there are limitations when it comes to the size of the parcel that can be delivered.

If your package doesn’t fit, USPS will hold your package aside. But – the hold only applies for ten business days. So if the package is unclaimed at the Post Office window after ten days, the parcel will be returned to the sender.

Postal boxes come in five sizes, listed below:

• X-Small - 3" x 5 1/2" x 14 3/4"
• Small - 5" x 5 1/2" x 14 3/4"
• Medium - 11" x 5 1/2” x 14 3/4"
• Large - 11" x 11" x 14 3/4"
• X-Large - 22 1/2" x 12" x 14 3/4"

If a customer enters their address as a postal box, you might reach out to them. Ask them for the size, and mention the 10-day pickup window if your package may not fit. This will also ensure customers claim their package at the counter rather than assuming it wasn’t delivered.

Easyship’s platform is designed to automatically comply with courier guidelines and restrictions, including those specific to P.O. Box deliveries. With Easyship, online store owners can effortlessly ship without worrying about complicated compliance issues.

Post Office Box Size and Weight Restrictions

PO boxes come in various sizes, each with its own weight restrictions. The most common PO box sizes are:

• Small: 5 inches x 5 inches x 14.75 inches (13.97 cm x 13.97 cm x 37.47 cm)
• Medium: 11 inches x 11 inches x 14.75 inches (27.94 cm x 27.94 cm x 37.47 cm)
• Large: 11 inches x 11 inches x 18.75 inches (27.94 cm x 27.94 cm x 47.63 cm)
• Extra Large: 22.5 inches x 11.5 inches x 14.75 inches (57.15 cm x 29.21 cm x 37.47 cm)

The weight restrictions for PO boxes vary depending on the size, but most have a maximum weight limit of 70 pounds (31.75 kg). It’s crucial to check with the carrier before shipping a package to a PO box to ensure it complies with the size and weight restrictions. This step helps prevent any issues with delivery and ensures that your package reaches its destination without any hitches.

Challenges of Shipping to PO Boxes

USPS is the only courier that ships to postal boxes reliably. However, there are a couple of cases in which FedEx can deliver, so keep these restrictions in mind:

• Limited courier choice: Other than USPS, the only way to deliver to PO boxes is via FedEx SmartPost. This service actually uses USPS for the final leg of delivery, which makes it possible to ship your order to your PO box
• International shipping is a hassle: FedEx Express is available to ship PO boxes to some international destinations and Puerto Rico. Though, you’ll need to provide a valid phone number or fax number
• Tricky tracking: The shipment might sit in its PO box for a while, meaning the tracking updates won’t update until the recipient picks it up. This issue can be frustrating for merchants looking to see if their customer received their items

Easyship’s innovative platform automatically detects PO box addresses from your end customers, making it easy for eCommerce entrepreneurs to identify customers who require this specific delivery option. This ensures that the correct shipping solution is automatically selected, saving valuable time and reducing the risk of failed delivery.

Related post: FedEx PO Box Shipping: What You Need to Know

How Easyship Can Help

Easyship allows eCommerce store owners to compare shipping rates from various carriers that deliver to P.O. boxes, including FedEx SmartPost and USPS. By leveraging this feature, businesses can find the most cost-effective shipping solution for PO box deliveries, minimizing shipping expenses and maximizing profitability.

With Easyship's platform, you can easily follow the steps outlined above. The essential address validation ensures accuracy and reduces the risk of shipping delays or returned packages. The platform is designed to comply with carrier guidelines and restrictions specific to PO box deliveries.

Overall, Easyship streamlines the shipping process, minimizes challenges and provides users with the tools to boost the efficiency and convenience of shipping to customers with PO boxes.

FAQs

1. Can you ship directly to a PO Box?

• USPS: All domestic USPS services—Ground Advantage, First-Class, Priority Mail, and Priority Mail Express—deliver to PO Boxes.
  
  
• Private carriers: Standard UPS® and FedEx® services don’t. Only hybrid “hand-off to USPS” products such as FedEx Ground Economy still reach PO Boxes; UPS dropped this option when SurePost ended in Jan 2025.
  
  

2. How do I address mail to a PO Box

(Use all caps, no punctuation.) 

Recipient Name

PO BOX 12345

CITY ST ZIP+4

3. Can I make all my mail go to a PO Box?
Yes. After you rent a box, file an online or in-person permanent Change-of-Address request and USPS will forward everything—even packages—for 12 months (extendable up to another 18 months for a fee). 

4. What’s the fastest way to send mail to a PO Box?
Priority Mail Express—overnight-to-2-day delivery to most PO Boxes, 365 days a year, with a money-back guarantee.

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