Address VerificationDirect Mail

PO Box vs. Street Address

By 8 September 2021September 10th, 2021No Comments
send direct mail to po box vs street address

PO Box vs. Street Address

The USPS makes regular deliveries to PO Boxes and street addresses all around the US. From a financial aspect, the USPS actually prefers delivering to PO Boxes over normal street addresses. As you can very well guess, it costs less for the USPS to make a delivery to a PO Box than to your home or street address because every letter goes through the post office, and there is no need for transporting the letters to the street address if it is addressed to a PO Box. All the USPS people have to do is deposit the postal mail in the PO Boxes, which is the same place where all the letters, including the ones addressed to the same PO Box, are sorted. So it is the same equivalence of us putting something in our home from one place to another.

send direct mail to po box vs street address

This article is the difference between delivering postal mails to PO Boxes vs. Street Addresses. We also discuss how you can get USPS to deliver your postal mails to the physical address and not your PO Box address. Similarly, we also discuss how you have your postal mail delivered to your PO Box address instead of your home address. Finally, we’ll also take you through how you can make UPS and FedEx deliver to your PO Box address as well.

Delivering Postal Mails Through USPS to a Physical Address Over a PO Box Address.

Have you ever wondered what happens to the postal mails that we sent where we put both the address of their PO Box and street address? Since we have already mentioned that the USPS actually prefers delivering to PO Boxes, it is hardly surprising that your posts will get delivered to the PO Box if someone has put both your home address and the PO Box address on the envelope sent to you. What do you do if you only mean adding the PO Box address as a backup address? So if you do have a preference as to where you want your postal mail sent, you must put that preferred address on the first line and then write the secondary or backup on the second line. You can even write “backup” so that there is no confusion about where to deliver the letter.

Now, at least some of you who are reading this are wondering whether it is really all it takes. Is it enough to simply write the physical address on the first line for it to be treated as the primary address? Well, the answer is yes. The proper formatting is all you need because USPS Pub. 28 says so. Thus, if the address has validated data in both the first line and second line and you have managed to list the physical address first, then you can be pretty much sure that your postal mail is delivered to the physical address and not the PO Box address.

Delivering Postal Mails Through USPS to a PO Box Address Over a Physical Address

Now, let’s consider the same mail, except you want your mail to be sent to a PO Box address instead of a physical address. All you have to do is swap those address lines and have your PO Box address written on the first line. Like the last case, we still have both two valid addresses, and by listing the PO Box address, you are informing the USPS that your priority is to have the letter delivered to the PO Box address.

Writing Both PO Box and Street Address in the First Address Line

We have already made it clear that the USPS prefers to deliver letters directly to the PO Boxes rather than physical addresses. We have also discussed how we can ensure that the letter is delivered either to the PO Box or street address by writing the primary destination as the first line of the address on the envelope. This begs the question, what happens if we write both the PO Box and street address on the first line? You can write the first address line using both PO Box and street address using one of the following two formats.

609 Seaport Rd PO Box 1408
Maine, ME 68200
Or PO Box 1408 609 Seaport Rd
Maine, ME 59538

What happens now is that such letters that don’t particularly follow a standard format for writing the address are subjected to a USPS standardization process. During this process, the address is converted to a standardized USPS address to accomplish easy and fast delivery of postal mails. The standardized address will look something like the following:

PO Box 1408
609 Seaport Rd
Maine, ME 68200

As you can see, here also the preference is given to sending mail to PO Box address over the physical address. From this, we can assume that the default process is to have the letter sent to the PO Box address. Therefore, if you need the letter you sent to reach the addressee at his/her physical address, you must write the same on the first address line. The best practice to adopt is to always write the primary address on the first line and the backup one on the second line, so there is no confusion.

Writing an Invalid & Valid Address in Different Address Lines

For a letter to be sent via USPS, the address must first be validated to be real and this will be done regardless of whether you’ve addressed the mail to a PO Box address or a street address. Let us take the example of the same address we used above but with a slight change. Consider the following two addresses.

PO Box 1408
23524 W. Vasco Square
Maine, ME 68200
23524 W. Vasco Square
PO Box 1408
Maine, ME 68200

As you can see, the two addresses above are the same except that the first two address lines have been swapped. Now, let’s say that Vasco Square is a nonexistent address or, in other words, an invalid address as far as USPS is concerned. So what happens if you use the wrong or invalid address? This is where things might be a little different than you might think. At least, some of you reading would have assumed that both addresses are undeliverable since they contain an invalid address line.

But, that would be a wrong assumption in this case. Here, the first address has a valid PO Box address in the first line, and hence it will be delivered to the same. In the case of the first address, the USPS will consider the second address line as “extra information.” As per the USPS, this extra information will help the delivery person. Therefore, additional information is not needed for the system that routes and processes the said mail.

Now let’s consider the case of the second address, which has an invalid first address line. In this case, the mail address is immediately classified as invalid and, therefore, undeliverable. This further underlines the importance of address standardization and validation, especially if yours is a company that sends out regular postal mails. Since postal mails are much more expensive than digital outreach programs using emails or text messages, companies could end up losing a significant amount of money if they keep sending posts to invalid addresses.

The smart way would be to avoid invalid addresses altogether. To do that, you’d need an advanced address verification tool like PostGrid. With a tool like PostGrid, you can easily filter out the invalid addresses from your database using a simple CSV file. Furthermore, PostGrid is CASS-certified which means the address validation is carried out using USPS’s official address database. By filtering out the undeliverable addresses, you can be sure that every mail sent from your company reaches its destination.

Writing an Invalid & Valid Address in the Same Address Line

Taking the same address as an example once again, let’s assume we write the address on the envelope combining the first and second address lines. The first address line will then look something like “PO Box 1408 16346 E. Vasco Square” or “23524 W. Vasco Square PO Box 1408”. In this case, the USPS system will first standardize the address as it normally does. Since the PO Box address is a valid one, the system detects this, brings it upfront, and assigns it as address line 1.

The invalid part of the address “16346 E. Vasco Square,” which was initially on address line 1, is pushed down to address line 2 by the USPS address standardization system. The USPS system includes the invalid part of the address in the second line despite knowing it is invalid. Why? Because as we have mentioned earlier, the system treats it as “extra information.” However, something that seems irrelevant to the system could still be necessary for the delivery person.

The USPS address verification system does not disregard the invalid address because the information could be important. Although the system’s working makes sense, it is by no means perfect. A better address verification system like PostGrid would be able to detect minor typos and self-correct the address to provide you with an accurate and complete deliverable address.

Sending Mail to PO Box via UPS and FedEx

As some of you may already be aware, private delivery companies like UPS and FedEx do not ship to PO Box addresses. They have a strict “delivery only to physical street address” rule, which stands in the way of PO Box owners receiving mail from the UPS or FedEx in their PO boxes. However, there is a simple solution to this problem. All you need to do to have UPS or FedEx deliver a direct mail to a PO Box address is to use a different format while writing the address for that post. This format is called a PO Box Street Address, and you can use it to send packages through any retailers and shipping companies to a PO Box address.

PO Box Street Address

The PO Box Street Address or PBSA is, in essence, the PO Box number combined with that particular post office’s street address. For example, suppose you want to send a mail to PO Box number 13 of a post office located at “1408 Vasco St, Maine, ME 68200”. In this case, the PBSA will look like this:

1408 Vasco St #13
Maine, ME 68200

A PBSA address pushed through an advanced address verification tool such as PostGrid will provide you with a standardized form of the PBSA. One notable difference in the standardized PBSA is that instead of saying “#,” it would say “unit,” for example, “1408 Vasco St Unit 13”. As long as you have PBSA, you can deliver the mail to a PO Box regardless of whether you have a Street Addressed mail or a PO Box addressed mail. Another point worth noticing about posts sent to PO Boxes is that if the mail sent to a PO Box is a large item, it is safely stored in the back room of the post office, and a slip is put on your PO Box to inform you about the same.

PBSA: Things to Note

Now that we know to send a letter to PO Box using PBSA, there are a few other things you should be informed about when using PBSA. For example, if your business uses a PBSA-address and later closes your PO Box, you are bound to submit a change-of-address form for the PO Box format and PBSA format. Furthermore, you should also make sure that both these forms have the same forwarding address.

In case you want to look up a PBSA address, you can submit the same to our advanced address verification API and request additional details. PostGrid will then furnish you with all the necessary details, including a “Box ID” field that you can use to ascertain whether the address you have is a PO Box or PBSA one.


Whether the mail sent out from your company is addressed to a PO Box address or a street address, it is still subjected to an address validation by the carriers like USPS. If the validation shows that the PO Box address or street address is not valid, then the post is not forwarded to the delivery person. This means that your business could end up losing valuable resources and money by sending out postal mails to invalid addresses. Companies can easily avoid this unnecessary expense and wastage of resources by using an advanced address verification tool like PostGrid. You can efficiently validate both PO Box and street addresses using advanced tools like PostGrid. This can, in turn, optimize your process, and you can even use PosGrid to automate the entire mailing process for optimal results.

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