PO Box or P.O. Box? Correct Spelling, Punctuation & Address Examples

If you are wondering whether to write PO Box or P.O. Box, both forms are correct. The difference is mainly a matter of punctuation and style.

PO Box is the simple, modern form, while P.O. Box is the traditional form with periods. Both abbreviations stand for Post Office Box, a numbered mailbox provided by a postal service for receiving mail.

For example, both of these forms can be understood:

PO Box 123

P.O. Box 123

If you are writing a modern mailing address and there is no specific formatting requirement, PO Box is usually the cleaner choice. However, when reproducing an official address, it is best to follow the format supplied by the postal service or organization.

PO Box or P.O. Box: Which Is Correct?

PO Box and P.O. Box are both correct forms of the abbreviation Post Office Box.

The main difference is punctuation:

• PO Box — unpunctuated form
• P.O. Box — punctuated form

The unpunctuated version is common in modern writing and addresses, while the punctuated version reflects a more traditional style of abbreviation.

PO Box

PO Box uses no periods after the letters.

Please send the application to PO Box 500.

This form is concise and easy to read, which makes it particularly useful in mailing addresses, forms, websites, and business documents.

P.O. Box

P.O. Box uses periods after both initials.

Please send the application to P.O. Box 500.

This is also a correct form and may still appear in older documents, established organizational styles, and traditional writing.

Quick Comparison

Form	Correct?	Description
PO Box	✅ Yes	Modern, unpunctuated form
P.O. Box	✅ Yes	Traditional, punctuated form
PO. Box	❌ No	Inconsistent punctuation
P.O Box	❌ No	Missing the second period
POBox	❌ No	Words incorrectly combined
P O Box	❌ No	Nonstandard spacing

Should You Write PO Box or P.O. Box?

If you simply need to choose one form, PO Box is generally the best modern choice.

It is shorter, clean, and easy to read. Many contemporary writing styles avoid periods in common abbreviations, which makes PO Box a natural choice.

However, there is no need to treat P.O. Box as an incorrect spelling. It is an established form and is still widely recognizable.

Which Form Is Better for Modern Writing?

For general modern writing, PO Box is a straightforward choice.

For example:

Our mailing address is PO Box 250.

The same sentence can also be written as:

Our mailing address is P.O. Box 250.

If you are creating a website, business form, letter, or other document without a required style, consistency matters more than choosing between the two forms.

Which Form Should You Use in an Address?

For a mailing address, PO Box is a clear modern format:

Maria Johnson
PO Box 250
Denver, CO 80202

If an official organization provides its address as P.O. Box 250, you can reproduce that format exactly.

The most important thing is to use the correct PO Box number, city, postal code, and other required address information.

What Does PO Box Stand For?

PO Box stands for Post Office Box.

A Post Office Box is a numbered mailbox associated with a post office. Instead of having mail delivered to a person’s home or business street address, mail can be addressed to the assigned PO Box.

For example:

John Smith
PO Box 456
Boston, MA 02108

In this example, 456 is the PO Box number.

P.O. Box Number Meaning

• A P.O. Box number is the unique number assigned to a rented mailbox at a post office.
• “P.O.” stands for Post Office.
• The number after “P.O. Box” identifies your specific box.
• For example, P.O. Box 125 means the box number is 125.
• A P.O. Box number is different from a street address.
• It is also different from a postal or ZIP code.
• You receive the number when you rent or are assigned a P.O. Box.
• The box is located inside a post office or postal facility.
• A P.O. Box can be used to receive eligible mail and correspondence.
• If a form asks for your P.O. Box number, enter your assigned box number.

What Is a PO Box Number?

• A PO Box number identifies a specific mailbox at a post office.
• It normally appears after the words “PO Box.”
• For example, PO Box 456 has the box number 456.
• The number is assigned by the postal service.
• It is not the same as your house or apartment number.
• It is not your postal code or ZIP code.
• Different customers can have different PO Box numbers.
• A PO Box can provide an alternative mailing address.
• You should use the exact number assigned to your box.
• If you do not have a PO Box, you generally do not have a PO Box number.

Is a PO Box the Same as a Postal Code?

• No, a PO Box and postal code are completely different.
• A PO Box identifies a specific mailbox at a post office.
• A postal code identifies a geographic delivery area.
• In the United States, a postal code is commonly called a ZIP code.
• A PO Box number belongs to an individual box.
• A postal code can be shared by many addresses.
• PO Box 125 and postal code 12345 represent different information.
• You should not enter a PO Box number where a postal code is requested.
• You should not use your postal code as your PO Box number.
• If a form asks for both, enter each one in its appropriate field.

Does Everyone Have a PO Box?

• No, not everyone has a PO Box.
• Most people can receive mail at their regular address.
• A PO Box is usually rented or assigned separately.
• Businesses may use PO Boxes for correspondence.
• Individuals may choose a PO Box for privacy or convenience.
• A PO Box can provide a separate mailing address.
• Having a postal address does not mean you automatically have a PO Box.
• PO Box availability depends on the local postal service.
• If you have never rented one, you probably do not have a PO Box number.
• You should only provide a PO Box number if one has actually been assigned to you.

PO Box vs. Mailbox

• A PO Box is a specific type of mailbox located at a post office.
• The word “mailbox” is a broader term.
• A home mailbox is usually located at or near your residence.
• A PO Box is located inside a post office or postal facility.
• Home mailboxes are associated with a physical property.
• PO Boxes are associated with a particular post office location.
• A mailbox may be owned or provided with a property.
• A PO Box is typically rented or assigned by a postal service.
• Not every mailbox has a PO Box number.
• Therefore, PO Box and mailbox should not automatically be treated as the same thing.

P.O. Box Number of My Location

• Your personal P.O. Box number cannot normally be determined from your location alone.
• A P.O. Box number is assigned to a specific customer.
• Your city or postal code does not automatically reveal your P.O. Box number.
• If you rent a P.O. Box, check your postal service documents.
• You may also find the number on correspondence addressed to your box.
• You can contact the post office where your box is located to confirm it.
• Your street address and P.O. Box number are separate pieces of information.
• A nearby post office may have many different P.O. Box numbers.
• If you are looking for a business’s P.O. Box, check its official contact information.
• If you do not have a P.O. Box, there is no personal P.O. Box number to provide.

PO Box or P.O. Box: Which Is Correct?

• Both PO Box and P.O. Box are commonly used.
• P.O. Box uses periods after the letters P and O.
• PO Box removes the periods for a simpler modern style.
• Both forms mean Post Office Box.
• Some organizations prefer PO Box in their address formats.
• Other style guides may use P.O. Box.
• Official forms may specify which format to use.
• The meaning does not normally change when the periods are removed.
• Choose one format and use it consistently.
• PO Box is a simple and widely recognized modern format.

Does PO Box Have Periods?

• The traditional form is P.O. Box.
• The modern simplified form is PO Box.
• Both forms are generally understood.
• The periods represent the abbreviation in P.O.
• P.O. stands for Post Office.
• Some postal services use PO Box without periods.
• Formal writing may sometimes prefer P.O. Box.
• Online forms often use PO Box.
• Follow the formatting requirements of the organization or postal service.
• For general writing, either PO Box or P.O. Box can be appropriate.

PO Box Spelling

• The standard spelling is PO Box.
• P.O. Box is also a commonly accepted form.
• The full term is Post Office Box.
• PO and Box are normally written as separate words.
• “POBox” without a space is not the usual spelling.
• PO means Post Office.
• Box refers to the assigned mailbox.
• You may see both PO Box and P.O. Box in addresses.
• Use consistent spelling throughout your article or document.
• When completing an official form, follow its stated address format.

PO and PS in an Address

• PO in “PO Box” means Post Office.
• PS is not the standard abbreviation for Post Office Box.
• The normal forms are PO Box and P.O. Box.
• P.S. commonly means “postscript” in ordinary writing.
• P.S. should not normally replace PO in a postal address.
• Address abbreviations can vary between countries.
• Postal services may publish specific addressing standards.
• When an address form provides a field label, follow that format.
• Do not guess an abbreviation if the official address is available.
• For a Post Office Box, PO Box [number] is the safest commonly understood format.

Abbreviation for PO Box

• The most common abbreviation is PO Box.
• P.O. Box is another widely used form.
• The complete term is Post Office Box.
• PO stands for Post Office.
• Box identifies the individual mailbox.
• PO Box appears frequently in postal addresses.
• P.O. Box is common in traditional formal writing.
• PO Box is convenient for modern digital forms.
• The postal service may have its own preferred formatting rules.
• Always use the actual PO Box number assigned to you.

Why Do People Use a PO Box?

Individuals, businesses, and organizations may use a PO Box for several reasons.

A PO Box can provide:

• A dedicated mailing address
• A secure location for receiving mail
• An alternative to using a home address for correspondence
• A consistent mailing address when a person moves
• A separate mailing address for a business or organization

The services available through a PO Box can vary depending on the postal provider and country.

PO or P.O.: Which Abbreviation Is Correct?

Both PO and P.O. are established ways of abbreviating Post Office.

The difference is punctuation rather than meaning.

PO = Post Office

P.O. = Post Office

Therefore:

PO Box = Post Office Box

and:

P.O. Box = Post Office Box

Modern writing often omits periods from familiar abbreviations, while traditional styles may retain them.

Why Does PO Sometimes Have Periods?

Periods have traditionally been used to show that letters are abbreviations.

For example:

P.O. = Post Office

In many modern styles, periods are omitted from familiar initialisms and abbreviations:

PO = Post Office

This is why both forms can be encountered in real-world writing.

How to Write a PO Box Address

When writing a mailing address, the PO Box line normally identifies the recipient’s mailbox.

A basic example is:

John Smith
PO Box 123
Chicago, IL 60601

The exact addressing requirements can vary depending on the postal service and destination, so follow the applicable postal guidelines when sending important mail.

PO Box Address Example

Here is a simple U.S.-style example:

Sarah Williams
PO Box 789
Phoenix, AZ 85001

The first line identifies the recipient.

The second line gives the PO Box number.

The final line provides the city, state, and ZIP Code.

Where Does the PO Box Go in an Address?

In a basic mailing address, the PO Box information is normally placed on its own line between the recipient’s name and the city, state, and postal code.

For example:

ABC Company
PO Box 1000
Dallas, TX 75201

The exact format can vary depending on the destination and postal service, so use the recipient’s stated address whenever one is provided.

Do You Need a Street Address With a PO Box?

Not necessarily.

A PO Box can serve as the mailing address for mail intended for that box. However, whether a street address is required or whether a particular delivery can be made to a PO Box depends on the sender, carrier, service, and destination.

If you are filling out a form, check whether it specifically asks for a street address, mailing address, or PO Box.

PO Box vs. Street Address

A PO Box and a street address are not the same thing.

A PO Box identifies a mailbox associated with a post office, while a street address identifies a physical location.

PO Box	Street Address
Identifies a numbered postal box	Identifies a physical location
Example: PO Box 123	Example: 123 Main Street
Used for receiving mail at a post office	Used to identify a building or property
Does not normally identify a person’s physical location	Identifies a physical location

For example:

PO Box 123
Chicago, IL 60601

is different from:

123 Main Street
Chicago, IL 60601

Can a PO Box Be Used as a Mailing Address?

Yes. A PO Box is specifically intended to provide a mailing address for receiving mail through the postal service that operates the box.

However, not every delivery service or sender necessarily handles PO Boxes in the same way. If you are expecting a package or completing an online form, check the relevant delivery requirements.

PO Box and Physical Address Are Not Always Interchangeable

A form may ask specifically for a physical address rather than a mailing address.

If it asks for a physical or street address, entering a PO Box may not satisfy the requirement.

If it asks for a mailing address, a PO Box may be appropriate.

Always follow the instructions provided by the organization or service.

Is PO Box Capitalized?

In a mailing address, PO Box is normally written with capital letters.

For example:

PO Box 500

The same applies to the traditional form:

P.O. Box 500

In ordinary prose, you may see variations depending on the writing style, but PO Box is a clear and conventional form.

Should “Box” Be Capitalized?

In a mailing address, Box is conventionally capitalized as part of the address designation:

PO Box 123

In ordinary prose, capitalization may vary depending on the style and sentence.

For example:

The company receives mail at its PO Box.

Common PO Box Formatting Mistakes

Several incorrect variations appear because writers are unsure where to place periods or spaces.

PO. Box

PO. Box mixes the unpunctuated and punctuated forms.

❌ PO. Box 123

Use either:

✅ PO Box 123

or:

✅ P.O. Box 123

P.O Box

If you use the traditional punctuated form, both initials should have periods.

❌ P.O Box 123

✅ P.O. Box 123

POBox

PO Box consists of two words.

❌ POBox 123

✅ PO Box 123

P O Box

The letters should not normally be separated by spaces.

❌ P O Box 123

✅ PO Box 123

po box

Lowercase po box may appear in casual digital searches or text, but a properly formatted mailing address normally uses:

PO Box 123

PO Box Examples

Here are examples showing how the term can be used in different situations.

In a Mailing Address

David Brown
PO Box 321
Austin, TX 78701

In a Sentence

Please send the completed form to our PO Box.

In Business Writing

The company receives all correspondence at its PO Box.

In Formal Writing

The organization maintains a Post Office Box for official correspondence.

Using the Traditional Form

Send all documents to P.O. Box 875.

All of these examples communicate the same basic concept, although the punctuation style differs.

PO Box in Formal and Professional Writing

Both PO Box and P.O. Box can be used in professional writing.

If your workplace, organization, publication, or client follows a specific style guide, follow that guide.

If there is no established preference, PO Box is a clean and modern choice.

For example:

Please mail the signed contract to PO Box 250.

There is no need to use P.O. Box simply because the document is formal. Formal writing does not require periods in every abbreviation.

Consistency Matters

The most important rule is to be consistent.

If you choose PO Box, use that style throughout the document:

PO Box 100
PO Box 200
PO Box 300

If a document follows a style that uses P.O. Box, maintain that form consistently:

P.O. Box 100
P.O. Box 200
P.O. Box 300

Avoid switching between styles without a reason.

PO Box and International Addressing

The term PO Box is widely understood in English, but postal addressing conventions can differ between countries.

For international mail, the safest approach is to follow the address exactly as provided by the recipient and use the formatting recommended by the relevant postal service.

For example, don’t assume that a U.S.-style city, state, and ZIP Code format applies to every country.

The punctuation in PO Box is generally a style question, while the correct placement of postal information can be a matter of local addressing requirements.

PO Box or P.O. Box: Quick Answer

If you need the answer quickly:

PO Box and P.O. Box are both correct.

PO Box is the simpler modern form without periods.

P.O. Box is the traditional form with periods.

Both mean Post Office Box.

If there is no specific style requirement, PO Box is usually a clear and practical choice. If you are copying an official mailing address, use the format supplied by the organization or postal service.

Frequently Asked Questions

Is PO Box or P.O. Box better?

Both are correct. PO Box is generally the cleaner modern form, while P.O. Box is the traditional punctuated form. If you have no specific style requirement, PO Box is a simple choice.

Should PO Box have periods?

No periods are required in the modern form PO Box. The traditional form P.O. Box uses periods. Both forms are correct.

Is PO Box correct?

Yes. PO Box is a correct abbreviation for Post Office Box.

How do you write PO Box in an address?

A basic format is:

John Smith
PO Box 123
Chicago, IL 60601

Follow the specific addressing requirements of the destination postal service when necessary.

What does PO Box stand for?

PO Box stands for Post Office Box.

Is PO Box the same as a mailing address?

A PO Box can be used as a mailing address, but the terms are not identical. A PO Box is a particular type of mailing address associated with a postal box.

Can a PO Box replace a street address?

It can serve as a mailing address in many situations, but it may not replace a street address when a form, service, delivery provider, or organization specifically requires a physical address.

Is “P.O. Box” still correct?

Yes. P.O. Box is still a correct and recognizable form of the abbreviation Post Office Box.

Is “PO. Box” correct?

No. PO. Box is not the standard form. Use PO Box or P.O. Box instead.

Is “P.O Box” correct?

No. If you use periods, the standard form is P.O. Box, with a period after both P and O.

Is “POBox” correct?

No. The correct form contains two words:

PO Box

Is “P O Box” correct?

No. The standard forms are PO Box and P.O. Box.

Is PO Box capitalized?

In a mailing address, PO Box is normally capitalized.

PO Box 123

Which is more modern: PO Box or P.O. Box?

PO Box is generally considered the more modern-looking form because it omits periods from the abbreviation.

Is PO or P.O. correct?

Both PO and P.O. are established forms. PO is the unpunctuated modern form, while P.O. is the traditional punctuated form.

Can I use PO Box in formal writing?

Yes. PO Box is appropriate in formal and professional writing. You do not need to use P.O. Box simply because a document is formal.

What is the difference between PO Box and Post Office Box?

There is no difference in meaning. PO Box is an abbreviation of Post Office Box.

Should I write PO Box or Post Office Box?

Use PO Box when you want a concise form, particularly in an address. Use Post Office Box when you want to spell out the term completely.

Can I put a PO Box and street address on the same address?

Sometimes an address may contain both types of information, but the correct format depends on the purpose of the address and the relevant postal or delivery requirements. If you are given an official address, reproduce it as provided.

Conclusion

PO Box and P.O. Box are both correct ways to write the abbreviation for Post Office Box.

The main difference is punctuation:

✅ PO Box — modern, unpunctuated form
✅ P.O. Box — traditional, punctuated form

If you are choosing a style for a modern mailing address, PO Box is a simple and clean option. If an organization or postal service provides its address as P.O. Box, you can use that format instead.

The forms to avoid are “PO. Box,” “P.O Box,” “POBox,” and “P O Box.”

Quick takeaway: PO Box and P.O. Box are both correct; the choice mainly depends on punctuation and style.