How to Write a Mailing Address - Format + Examples

stack of letters with Postal Address Formats

How to write a mailing address is determined by the mailing address format of your country, the destination country, and the type of address you're sending to. We’ll cover the steps to write several types of addresses including standard mailing addresses, apartments, PO Boxes, APOs, and FPOs.

A Mailing Address Format is a set of spelling, abbreviation, and formatting guidelines, created and maintained by a country's postal authority for use within local mail delivery systems. The official postal address format in the US is run by the United States Postal Service (USPS).

Formatting an address correctly on your envelope, postcard, or parcel is essential for accurate delivery. Equally important, is verifying the mailing address is complete, valid, and deliverable by the local postal service.

We've included useful tools to correct, verify, and standardize your addresses to authoritative formatting guidelines in the US and for 240+ countries worldwide.

Try them now, or continue reading to learn more about how to write a mailing address, address formats and see address formatting examples for different address types.

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In this article, we’ll cover:

How To Write a Street Address

An airplane that begins its journey even one degree off can end up miles and miles away from where it is supposed to be. The same can be said about an address that has a single component in the wrong place, omitted, or simply incorrect.

What things are most important when trying to ensure that your letter, package, or postcard gets to where it needs to go? What if you’re trying to send to a military address? What about new addresses, or urban addresses? What if you’re sending something overseas to an international address? We’re going to go over several postal address examples to answer these questions.

If you’re looking for details on how to correctly abbreviate street names such as “street”, “avenue”, “parkway”, etc. we’ll go over that information as well.

Mail in a mailbox

As a child I remember asking my parents why I never got any mail. “You have to send mail to get mail.” my father would say. So it was at a young age that I first wrote my grandmother's street address on an envelope. It wasn’t until years later that I began to wonder what the components of an address were, and how the formatting mattered.

If you need to write a mailing addresses for a domestic address, or a letter from a United States address to another United States address, it’s quite simple:

Recipient’s Name
Building Number | Street Number/Name
City Name, State Abbreviation | Zip Code

Where should this information go on the envelope? Smack dab in the center. Here’s an example of a simple letter in an envelope being sent domestically.

Dr. Peter Venkman
2335 S State St
Provo, UT 84606

If you're not sure of some of the components of the recipient's address you can get that via an address validation tool like the one that you can use for free at Smarty. It is important to get the City, State, and ZIP Code as accurate as possible because the USPS automated mail sorters process addresses from the bottom up. Mixing up a Zip Code is that single degree that could get your letter sent to the wrong side of the country, or returned to you.

How to Write an Apartment Address

apartment mailboxes

Things get a little bit more complicated when you add an apartment number or building to the mix. While most of the address stays the same, you’ll now add the apartment number at the end of the street line. So your address would now look like this:

Recipient’s Name
Building Number | Street Number/Name | Apartment Number
City Name, State Abbreviation | Zip Code

The same rules apply for suites, floors, or building numbers. This is especially important to include—and do so correctly—because if you send a letter to your cousin Cynthia at her apartment building, how is the postman supposed to know which of the 500 units to deliver the letter to? Or what if you are trying to get those accident reports to the correct insurance company in the skyscraper on Broadway in New York, but you don’t have the floor number? Here’s how you’d do it correctly.

Alleghany Insurance
1411 Broadway Fl 34
New York, NY 10018

Notice the abbreviation for “floor” is FL. Likewise the abbreviation for Apartment is Apt. and for Suite it is Ste. If you are curious about the correct abbreviation for states, apartments, or anything address related, you can get it in an address validation tool like the one that you can use for free at Smarty.

first postcard example

How to Write a Postcard Address

Ah yes, the postcard. The cheapest souvenir one can send from their favorite photogenic landmark. What little tricks are necessary for these bad boys to be sent to the correct address? What are the tricky secrets one should know when sending this to their grandma?


The rules for a postcard are the same as a regular address. Just make sure you write it on the cute little lines beneath the postage stamp.

How To Write a PO Box Address

In areas where there may not be door to door delivery services you can often gain access to a PO Box or Post Office Box. You may also use a PO Box as a business for more secure delivery of mail. Typically, these are rented from the Post Office directly with a selection of size options.

There are a few tricks to sending to a PO Box as they don’t require all of the same components as a regular street address. Here’s the example:

Recipient’s Name
PO Box Number
City, State | Zip Code

To be clear, you do actually write the words “PO Box” on the envelope, followed by the PO Box number. For example: PO Box 123456.

It is important to make sure you have the correct Zip Code when sending to a PO Box. Other than the PO Box number, the only identifier for where this letter should go is the city, state, and ZIP. Large cities may have more than one Post Office and you want to make sure it is as simple as possible for the automatic sorting machines. If you’re not sure about the Zip Code on your address (PO Box or not) you can run it through an address validation tool to see what to put.

How to Write a Military Address

stack of military letters

The Armed Forces have their own military address format to ensure soldiers are able to receive their mail as they are moved around the world. They do this by the use of various Post Office types; Air/Army Post Office (APO), Fleet Post Office (FPO), and Diplomatic Post Office (DPO).

Since each of the military addresses is handled by its dedicated postal channel there is no need to state the city or state when sending mail to this type of address. Instead you would list the Post Office abbreviation such as APO, and the acronym that indicates the recipient’s duty station. Here’s an example:

PFC Franklin Johnson
PSC 3 BOX 5000
APO AE 12301-8871

You’ll notice there is a ZIP+4 at the end of that address. It is very important to include the 9-digit zip+4 when sending to military addresses.

How to Write a Return Address

second postcard example

While it’s not required to have a return address on your outbound mail, it is still a good idea to include it. If for any reason your letter is unable to be delivered, the postal service can return it to you if they have this return address. If there isn’t one… It ends up in the trash.

A return address should be the same as a standard postal address, but with your information on it. For example:

Sender’s Name
Building Number | Street Number/Name
City Name, State Abbreviation | Zip Code

The location of a return address is typically in the top left corner of the envelope. It is of value to note that you can include a return address on postcards as well, not just envelopes or percels. For a postcard you would either put it in the very top left corner of the card, or in the top left corner of the right half of the card.

A name is not required on the return address, but it may be useful if you are sending from a business or from a place where you are not the only person at the address.

Where to Put a Stamp On a Letter

In the top right hand corner.

This is a general rule of course. Whenever you’re dealing with standardized and machine-automated systems there are a few additional rules to consider.

If mailing to Japan for instance, you’ll want to check to see if your envelope is vertically oriented, or horizontal oriented. In a standard horizontal orientation the stamp goes in the top right hand corner. On a vertically oriented letter you’d place it in the top left corner.

In the US your first stamp goes in the top right hand corner, but if you need additional postage you can place the stamps next to the first one, growing out from the top right hand corner. Don’t forget to leave the bottom inch or so of your envelope bare so that the automated mail processors can print barcodes in that area.

USPS International Address Example & Format

There’s a trick to sending international mail. The problem is the differences in language, ordering of address components, and other local requirements. The solution is to ensure you’re utilizing the latin character set using a process called transliteration. The reasoning is simple: universal understanding to increase the likelihood of correct delivery.

Where a US address would have no more than three lines (name, street address, region) international addresses are more likely to have five lines. For example if you are sending a letter from the United States to England it might look like this:

Anglo American Woodsmith Project
Resolution House
Lake View
YO11 3ZB

As far as placement goes, addresses sent internationally should have some space on all sides for additional information placed there by the Post Office. Much like the United States, many country’s postal services use machines to process mail and will print barcodes on the envelopes in the empty space around the address.

USPS Address Format Checker

As discussed earlier it is extremely important to ensure that your address has been validated, verified, and standardized before you stick on a parcel and ship it. With international mail becoming easier to send and more important for global businesses, you need an address checker that you can trust.

Smarty’s USPS Address Format Checker is the fastest and most reliable address validation tool on the planet. With the ability to run millions of addresses through at a time you can clean up your database with the snap of your fingers. You can also set up the Smarty Address Autocomplete API to check the addresses when they are input into your system. You can try it for free today!

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