How to Write an Apartment Address Perfectly

If you're new to apartment living, you might not know how to write an address with an apartment number. Use these tips to format apartment mailing addresses correctly so your mail arrives quickly and without delays.

If you're unclear about general guidelines for writing addresses, start with this helpful video from the US Postal Service:

Quick Answer: Apartment Address Format

Use USPS formatting when writing apartment addresses in the United States. For example:

JANE DOE 123 MAIN ST APT 2 NEW YORK NY 11111-1234

Rule: Use USPS abbreviations, ALL CAPS, and no punctuation except the ZIP+4 hyphen.

How to Write an Apartment Address

Address Anatomy

Understanding the parts of an address makes formatting much easier. USPS addresses typically include the following elements:

The Essential Apartment Address Formula

The simplest way to write an apartment address is:

Recipient name Street address + apartment unit City, state, ZIP (preferably ZIP+4)

Example: JANE DOE 123 MAIN ST APT 2 NEW YORK NY 11111-1234

Steps:

1. Write the recipient's full legal name on the first line.
2. Write the street number, name, and apartment unit (with the APT abbreviation) on the second line Example: 123 Main St, Apt 2
3. On line three, write the state, city and zip code, including the 4 digits at the end if you know them. Example: New York, NY 11111

Key rule: The apartment unit stays on the same line as the street address.

How to Use "Apt" in an Apartment Address

"Apt" is a common abbreviation for an apartment that is always acceptable when you write an address. It goes on the second line next to the street number and name. You can also write out "Apartment," but abbreviations are actually preferable, which we explain below in more detail.

Many people place the apartment number on the third line, and include the city and state/province on a fourth line, but this is not technically correct. However, you will usually receive your mail if your address is written this way. You can also utilize the third line if you're short on space in the second.

Should I Put the Apartment Number Below the Street Number?

Your apartment number should go next to the street number and name. The third line actually has another purpose, but most people don't use it that way. The USPS says people should reserve the second line for special designators like "care of" or special handling instructions. For example:

Jane Doe

123 Main St, Bldg E, Apt 2

c/o John Doe

New York, NY 11111

Want more reassurance that you're on the right track? Check out this great video directly from USPS on writing addresses correctly:

Common Abbreviations

Abbreviating common words actually helps the postal service manage mail more easily. Abbreviations such as BLDG for building or APT for apartment are called “secondary address designators," and they identify a specific unit inside a building.

Use standardized abbreviations and do not add periods.

Here are some of the most common secondary address designators for the US postal service:

In the case of "Unit," there is no abbreviation. However, it still serves as a critical address designator.

Less Common Abbreviations

• Basement – BSMT
• Front – FRNT
• Lobby – LBBY
• Hanger – HNGR
• Slip – SLIP
• Lot – LOT
• Pier – PIER
• Rear – REAR
• Side – SIDE
• Front – FRNT
• Lower – LOWR
• Space – SPC
• Trailer – TRLR
• Key – KEY
• Office – OFC
• Space – SPC

Correct vs. Incorrect Apartment Address Formatting

International Apartment Addresses

Different countries have different address layouts. Research the recipient's country and write the address in the local format. This typically involves putting the recipient's name on the first line, followed by building/apartment number, street, city/town, state/province (if applicable), postal code, and country name written in ALL CAPS.

When sending international mail from the United States:

• Use the destination country's preferred format
• Write the country name in English
• Place the country on the final line in ALL CAPS

Example: JANE DOE 123 MAIN ST APT 2 TORONTO ON M4B 1B3 CANADA

Step-By-Step Instructions for Writing an Apartment Address

1. Place the Address in the Center of the Envelope

Centering the delivery address helps automated postal scanners read the address quickly.

Apartment Address Tip: Ideally you want to use as few lines as possible for the delivery address.

2. Start With the Recipient's Full Name

Use the full name associated with the apartment.

For example:

Jane Doe 123 Main St, Bldg E, Apt 2 New York, NY 11111

Apartment Address Tip: Using legal names for apartment addresses is also wise, as they’ll send any forwarded mail to the correct location.

3. Write the Street Address and Apartment on One Line

Keep the apartment unit on the same delivery line as the street address.

For example:

Jane Doe 123 Main St, Bldg E, Apt 2 New York, NY 11111

Apartment Address Tip: Remember to add a comma after the street address when you address a letter to an apartment.

4. Add the City, State, and ZIP Code

Use two-letter state abbreviations and include ZIP+4 when available.

Example: NEW YORK NY 11111-1234

5. Add Recipient’s Country for International Mail

For international mail, include the country on the final line in ALL CAPS.

For example:

Jane Doe 123 Main St, Bldg E, Apt 2 New York, NY 11111, USA

6. Write Your Return Address

Place your return address in the top left corner of the envelope using the same format.

For example:

John Smith 456 Ocean Ave, Bldg A, Apt 9 Los Angeles, CA 90001

Common Mistakes When Writing an Apartment Address

Now that you know how to format apartment address details for mail, it’s important to address some common mistakes.

Using Commas and/or Periods in the Wrong Place

Avoid commas and periods in delivery address lines.

Incorrect: 123 MAIN ST, APT 2

Correct: 123 MAIN ST APT 2

Putting the Apartment Number on Its Own Line

The apartment number should remain on the same line as the street address whenever possible.

Forgetting Neat Handwriting

Remember your mail carrier needs to be able to read your writing to ensure proper delivery. Take the time to write neatly, or consider printing a label as an alternative option.

Inserting the Wrong ZIP Code

If you learn how to write a letter to an apartment but put in the wrong ZIP code, it won’t be delivered properly. Pay close attention to these numbers to get them right the first time.

What Happens if You Write an Address Incorrectly?

In the worst case scenario, an address written incorrectly will simply not arrive at its destination, and instead will be returned to the sender. In some cases, USPS will still be able to deliver the package even if the address is slightly incorrect. However, making sure you include all the elements we mentioned above, and ensuring you have the sender's proper legal name will go a long way toward preventing mistakes and delays.

And, don’t forget, if you ever need to file a claim for package theft, your new skill will come in handy. These are enough reasons to master the art of the apartment address format!

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Apartment Address FAQs

What Happens if You Don’t Put the Apartment Number on the Envelope?

If you don’t include the apartment number on the envelope, the mail carrier won’t know which mailbox to deliver it to. In this case, the mail will likely be returned to the sender.

How Do You Write an Address That Has Both a Building and Apartment Number?

You can add the building number before the apartment number, if it’s included in the address.

For example:

Jane Doe

123 Main St, Bldg E, Apt 2

New York, NY 11111

How Do You Write the Floor Number in an Address?

A floor number in an apartment address will come before the unit number.

For example:

Jane Doe

123 Main St, Fl 1, Apt 2

New York, NY 11111

What If My Mailing Address Zip Code is Different From My Physical Address?

If you live on the border of a town or county, your physical address and mailing address may have different zip codes. Defer to the mailing address when sending or receiving letters or packages. The postal service offers zip code lookup if you need the zip code for your mailing address.