Postal Address Example: Getting It Right the First Time

If you’ve ever had a letter returned to you stamped “undeliverable”, you know the frustration of a badly written address. A postal address isn’t just a formality—it’s the critical set of details that tells the postal service exactly where to take your mail. Whether you’re sending a postcard across town or a package to international destinations, a clear and accurate mailing address is the difference between fast, correct delivery and delays, lost items, or customs headaches. To ensure your mail is properly addressed and reaches its destination, especially when using unique identifiers like ZIP+4 codes or specific recipient information, following the correct format is essential.

In the United States, the official postal address format is defined by the US Postal Service (USPS) to ensure their automated sorting systems can read your recipient’s address quickly and accurately. But the same principles apply worldwide—every country’s postal authority has specific rules for domestic address layout, international address formats, and even how to write a po box address or military destination. Each country's postal authority establishes the official address format and guidelines to ensure mail is properly addressed and delivered according to that country's postal regulations.

In this guide, we’ll break down every type of address—physical addresses, apartment and business address layouts, military addresses, and more—complete with real-world postal address examples. You’ll also learn how to avoid common mistakes, follow address format standards, and ensure your mail reaches the right person, the first time.

💡 Want to skip the manual formatting? LettrLabs can automatically verify and format every address before sending mail so you never worry about undeliverable items again. See how our Direct Mail Automation works for bulk and one-off campaigns.

Why the Correct Postal Address Matters

Every piece of mail—whether it’s a birthday card, an invoice, or a bulk marketing campaign—starts its journey with one thing: the postal address. The more accurate your address format, the easier it is for the postal service to sort and deliver it to the right place. Accurate and well-formatted delivery addresses help ensure successful mail delivery, reduce errors, and comply with postal guidelines.

When you include the right details—street number, street name, city state and zip, and if needed, country name—you’re giving sorting machines and carriers exactly what they need to achieve correct delivery. Leave something out, and your item might get delayed, sent to the wrong place, or returned entirely.

For physical addresses in the U.S., the US Postal Service has strict guidelines on the state and zip code placement, spacing, and even capitalization. Including correct ZIP codes as part of the address format is essential to ensure accurate routing of mail and to avoid delivery delays or returns. Abroad, each country’s postal authority uses its own structure, which means you can’t assume the format you use domestically will work for international address layouts.

Getting the address wrong doesn’t just slow things down—it can cost you. Lost mail means lost opportunities, wasted postage, and in business contexts, disappointed customers.

💡 If you’re sending high-volume campaigns, LettrLabs can automatically verify every mailing address before your mail goes out—saving you time and postage. Learn more about our Tracking & Analytics Tools for real-time delivery insights.

Understanding the Components of a Complete Address

No matter where you’re sending mail, a complete address follows a logical order so postal workers and sorting machines can read it fast. Whether it’s a domestic address, apartment address, or PO box address, every line has a specific role. Mailing addresses must follow a standardized order, with each following line containing specific address components for clarity and accuracy.

First Line – Recipient’s Name and Job Title

The first line should always show the recipient’s address starting with their full name. For a business address, add a job title or department name to help route the mail internally.

• Correct:
  ATTN: Sarah Lopez, Marketing Director
• Avoid:
  Marketing Office (too vague)

Using capital letters throughout the address makes it easier for automated systems to read, though it’s not mandatory everywhere.

Second Line – Street Address or PO Box

This is where you specify the delivery point:

• For physical addresses, include the building number, street number, and street name.
• For apartment addresses, add the apartment number or unit numbers right after the street info.
• For PO box addresses, replace the street line entirely with “PO Box” followed by the po box number.

Examples:

• 1246 Maple Street Apt 5B
• PO Box 6234

Next Line – City, State, and ZIP/Postal Code

Write the city state and zip on one line. In the U.S., use the five digit zip code, and optionally the ZIP+4 for even more precise routing.

• Example: Austin, TX 78704
  In international mail, this line may also include the province abbreviation or additional postal code formats depending on the country.

Country Name for International Destinations

When sending to international destinations, the destination country should be the final line, written in capital letters. This ensures the country’s postal authority can direct the mail correctly upon arrival.

Example:
Melbourne VIC 3000  
AUSTRALIA

💡 LettrLabs can handle everything from apartment address formats to international address layouts automatically—so you don’t have to worry about the wrong place or missing fields. See our full list of Direct Mail Formats that can be sent to verified addresses worldwide.

Domestic Address Format (U.S.)

When you’re mailing within the United States, a domestic address needs to follow the official postal address format set by the US Postal Service. Even small changes—like putting the state and zip code on the wrong line—can delay your mail delivery or cause it to be returned.

The USPS recommends writing your mailing address in all capital letters, without punctuation, and with a single space between each part of the city state and zip. This format works for everything from a regular address to a business address.

Here’s a correct U.S. postal address example:

JAMES ANDERSON
4527 OAKRIDGE DRIVE
DENVER CO 80205

Key USPS guidelines for domestic addresses:

• Keep the street number and street name together on the same line.
• Avoid extra symbols (like “#”)—use abbreviations such as APT for apartment or STE for suite.
• Always include a five digit zip code, and optionally a ZIP+4 for better routing.
• For faster sorting, place the sender's address (return address) in the top left-hand corner of the envelope. This is the standard placement for the sender's address according to USPS guidelines. The stamp should be placed in the top right-hand corner.

Common mistakes to avoid:

• Placing the apartment number on a separate line (should be with the street).
• Missing state and zip code.
• Using lowercase or excessive punctuation, which slows down automated sorting.

💡 If you send bulk domestic address mail, LettrLabs can verify every postal address against USPS data before printing—helping you cut waste and keep costs down. Learn more on our Direct Mailing Lists guide.

Apartment Address

Adding an apartment number to your mailing address is simple, but it has to be placed correctly to avoid delays or misdelivery. The USPS prefers the apartment address details to be on the street line, directly after the street number and street name, so sorting machines can read the entire delivery point in one pass.

Correct format:

KAREN SMITH
1287 PINE GROVE RD APT 204
CHICAGO IL 60614

Tips for apartment addresses:

• Always write apartment number as APT followed by the number (or use STE for suite, FL for floor).
• For large apartment buildings, including unit numbers and floor number is essential for correct delivery.
• In large cities, correctly identifying the unit and floor number is especially important for PO Box deliveries and proper sorting, since multiple post offices may serve the same area.
• Avoid putting the apartment building name in place of the street address—if you include it, it should go above the street line.

Wrong format example (causes delays):

KAREN SMITH
APT 204
1287 PINE GROVE RD
CHICAGO IL 60614

Placing the apartment detail on a separate line makes it harder for the postal service to scan and sort efficiently.

💡 If you frequently send mail to apartment addresses, LettrLabs can standardize your mailing lists to match USPS guidelines—ensuring every postal address is ready for fast delivery. See how our Direct Mail Automation works.

Business Address

A business address follows many of the same rules as a regular address, but it usually includes extra details to make sure mail reaches the right person inside the company. This might be a job title, department name, or even an internal mail stop.

Correct business address format:
JENNIFER CLARK, OPERATIONS MANAGER
BRIGHTWAY SOLUTIONS INC
725 LAUREL AVE STE 320
SAN DIEGO CA 92101

Best practices for business addresses:

• Always include the recipient’s name and, if possible, their job title to ensure accurate delivery inside the organization.
• Add the company name directly under the name line.
• Use STE for suite, FL for floor, or other USPS-approved abbreviations instead of symbols like “#.”
• Keep all elements in capital letters for faster scanning by sorting machines.

Common mistake:
Leaving off the company name can slow down delivery, especially in large office buildings with multiple businesses sharing the same physical address.

💡 If you’re sending marketing materials to a business address list, LettrLabs can verify every contact before printing, so your mail reaches decision-makers. Check out our Outbound Lead Generation strategies for B2B campaigns.

PO Box Address

A PO box address is used when the recipient receives mail at a post office box instead of a street location. This is common for businesses, rural residents, or in countries where physical addresses aren’t standard.

Correct PO Box format:
MICHAEL RYAN
PO BOX 4721
BOISE ID 83707

Key rules for PO box addresses:

• Always write “PO Box” followed by the po box number—never abbreviate it differently.
• Do not include a street address on the same line as the PO box. If you need to list both, they must be on separate lines (and USPS will generally use the PO Box for delivery).
• Include the city state and zip exactly as you would for a regular address.

Common mistake:
Mixing the building number and PO box number on the same line can confuse sorting systems, leading to misdelivery.

💡 If you maintain a list of PO box addresses for customers or leads, LettrLabs can help you clean and segment it for better targeting. Learn more in our Direct Mailing Lists guide.

Military Addresses

Military addresses have their own rules because they’re handled through a dedicated postal channel separate from standard domestic and international mail. These addresses are used for mail going to APO (Army or Air Force Post Office), FPO (Fleet Post Office for the Navy), or DPO (Diplomatic Post Office). While military addresses are formatted similarly to regular addresses, there are specific distinctions for military mailing procedures to ensure proper delivery.

Correct military address format:SFC JASON THOMAS
UNIT 2050 BOX 4190
APO AE 09375-1234

Key rules for military addresses:

• Always include the recipient’s full name and rank—do not use “Any Service Member” (it’s no longer permitted).
• Replace the city name with APO, FPO, or DPO, and replace the state with the recipient’s duty station abbreviation:
• AE – Armed Forces Europe
• AP – Armed Forces Pacific
• AA – Armed Forces Americas
• Always use a nine-digit ZIP code for correct delivery.
• Never include the actual physical address of the military base.

Common mistakes to avoid:

• Writing the wrong place (city/state) instead of the correct APO/FPO/DPO format and recipient's duty station abbreviation.
• Leaving out the unit or box number, which can cause mail to be delayed or returned.

💡 LettrLabs can ensure military addresses in your database meet USPS guidelines before mailing—reducing waste and avoiding undeliverable pieces. See how our Direct Mail Automation works for campaigns with APO, FPO, and DPO recipients.

International Address

Writing an international address requires following the address format guidelines of the destination country. Each country’s postal authority has its own rules, and copying your domestic address style often leads to delays or undeliverable mail.

For most international destinations, a correct format includes:

1. Recipient’s name (include job title if needed for a business address).
2. Street address or po box address with building number, street number, and street name.
3. City name and any required province abbreviation or regional detail.
4. Postal code (format varies by country).
5. Country name in capital letters as the last line.

Example – UK address:
EMILY CARTER
45 WELLINGTON ROAD
LONDON SW1A 1AA
UNITED KINGDOM

Example – Australia address:
OLIVER WRIGHT
32 RIVER VIEW STREET
SOUTHPORT QLD 4215
AUSTRALIA

Example – Canada address:
SOPHIE MARTIN
89 KING STREET W APT 7
TORONTO ON M5V 3K4
CANADA

Tips for sending international mail:

• Match the postal code and layout exactly to the country’s standards.
• Never translate the country name—write it exactly as the postal authority requires.
• Some countries require a po box number instead of a physical address, so check before mailing.
• Always ensure your return address is included in the top left corner for undeliverable items.

💡 Sending mail to multiple international destinations? LettrLabs verifies every international address against official postal databases so your mail arrives on time. Learn more about our Integrations with shipping and CRM platforms.

Common Address Formatting Mistakes

Even a small error in your address format can send your mail to the wrong place or cause it to be returned. Here are the most frequent mistakes people make — and how to avoid them.

1. Missing postal codeLeaving out a postal code (or using the wrong one) is one of the top reasons for delayed delivery. In the U.S., always include the five digit zip code—and consider ZIP+4 for more precise correct delivery.

2. Apartment number in the wrong placeFor an apartment address, the apartment number belongs on the street line after the street number and street name, not on a separate line.

3. Forgetting the return addressWithout a return address in the top left corner, undeliverable mail has no way back to you. This is especially risky for international mail and po box addresses.

4. Mixing formatsCombining a physical address and PO box address on the same line confuses sorting systems. If you must list both, put them on separate lines.

5. Wrong abbreviationsUsing “#” instead of “APT” or “STE” isn’t USPS-approved. The wrong abbreviation can slow mail delivery or lead to scanning errors.

6. Country name errors for international destinationsMisspelling or translating the country name incorrectly can cause customs holds or returns. Always follow the country’s postal authority standards.

7. Illegible or inaccurate recipient's addressNot writing the recipient's address clearly and accurately, or placing it incorrectly, can result in delivery errors. Always double-check the recipient's address and position it in the center of the envelope.

💡 Tip: For best results, write addresses using black ink to ensure clarity and readability, especially for official or formal mailings.

💡 LettrLabs automatically checks every postal address for formatting errors—fixing them before sending mail. Learn more about our Direct Mail Automation and list verification tools.

Return Address Format

A return address isn’t always mandatory for domestic mail, but it’s critical for correct delivery when something goes wrong. For international mail, the USPS requires it so undeliverable items can be sent back without delay.

Where to place it:

• Always put the sender’s address in the top left corner of the envelope or package.
• Use the same address format rules as you would for the recipient’s address.

Correct return address format example:
JULIA MURPHY
112 WEST OAK AVE
AUSTIN TX 78704

Best practices:

• Use capital letters and no punctuation for USPS automation.
• Include a postal code (or state and zip code) for domestic address mail, and the full country name for international address mail.
• If you’re sending from a business address, list the company name under your name for brand recognition.

💡 Including a return address on every piece of mail is an easy safeguard. LettrLabs can store and automatically print your preferred sender’s address on every campaign—see our Direct Mail Automation tools.

Postal Address Examples

Sometimes the fastest way to understand an address format is to see it in action. In the examples below, each following line represents a specific component of the postal address format, such as the recipient's information, address components, and country details. Below are examples for the most common types of postal addresses—ready to copy and adapt.

Domestic Postal Address Example

JAMES ANDERSON
4527 OAKRIDGE DRIVE
DENVER CO 80205

Apartment Address Example

KAREN SMITH
1287 PINE GROVE RD APT 204
CHICAGO IL 60614

Business Address Example

JENNIFER CLARK, OPERATIONS MANAGER
BRIGHTWAY SOLUTIONS INC
725 LAUREL AVE STE 320
SAN DIEGO CA 92101

PO Box Address Example

MICHAEL RYAN
PO BOX 4721
BOISE ID 83707

Military Address Example

SFC JASON THOMAS
UNIT 2050 BOX 4190
APO AE 09375-1234

International Address Example – UK

EMILY CARTER
45 WELLINGTON ROAD
LONDON SW1A 1AA
UNITED KINGDOM

💡 LettrLabs can print, verify, and send to any of these formats—whether you’re mailing to domestic addresses, apartment addresses, or international destinations. Explore all our Direct Mail Formats for your next campaign.

USPS Guidelines for Physical Addresses

For mail delivered within the U.S., the US Postal Service has strict rules for writing physical addresses so automated sorting systems can read them quickly and accurately. Following these guidelines reduces delays, improves correct delivery, and keeps your mail from being flagged as incomplete.

Key USPS standards:

• Write all lines in capital letters for maximum machine readability.
• Use black ink when writing addresses to ensure clarity and optimal machine readability.
• Place the street number before the street name (e.g., 1246 MAPLE STREET).
• Avoid punctuation—don’t use commas, periods, or symbols like “#” for apartment number or suite.
• Leave one space between the city name and state abbreviation, and two spaces between the state and ZIP code.
• Use official abbreviations for street suffixes (ST, AVE, BLVD) and directionals (N, S, E, W).
• Include a five digit zip code, or ZIP+4 for more specific sorting.
• If mailing to a PO box, use the correct “PO BOX” format with the po box number on its own line.
• Ensure your return address is in the top left corner of the envelope.

Example of a compliant USPS address:SARAH BROWN 1246 MAPLE STREET APT 12B PORTLAND OR 97205

💡 LettrLabs automatically formats and validates every postal address before printing, so you meet USPS standards every time. Learn more about our Direct Mail Automation features.

Tips for Sending Mail Correctly

Even if you’ve followed the right address format, small details can still make or break your delivery success. Use this quick checklist to make sure your postal address is ready before sending mail:

1. Double-check the recipient’s address — confirm the street number, street name, city state and zip, and any apartment number or po box number.
2. Verify the postal code — in both domestic addresses and international addresses, a missing or incorrect postal code can cause major delays.
3. Use a return address — place your sender’s address in the top left corner for all mail, especially for international destinations.
4. Add correct postage stamps — without them, your mail won’t move, no matter how perfect the address is.
5. Avoid overcrowding the envelope — keep the delivery address in a clean, clear space so it’s easy for the postal service to scan.

💡 LettrLabs offers tracking and analytics tools so you’ll know exactly when your mail is delivered. See how you can monitor campaign performance in real-time with our Tracking & Analytics Tools.

Address Verification and Normalization

Even the most carefully written postal address can fail if the details don’t match the postal service database. That’s where address verification and normalization come in.

Address verification checks a mailing address against official data from the country’s postal authority to confirm it’s valid. This ensures your mail is routed to the right physical address or PO box address before it ever leaves your hands.

Address normalization goes a step further—it cleans up your address format to match standardized rules, such as:

• Correcting misspelled street names or building numbers.
• Converting informal apartment listings into USPS-approved abbreviations (APT, STE, FL).
• Adding missing postal codes or state and zip code details.
• Adjusting formats for international destinations so they follow local conventions.

For high-volume mailing, skipping this step can lead to undeliverable pieces, wasted postage, and missed deadlines—especially for military addresses and mail sent via a dedicated postal channel.

💡 LettrLabs automatically verifies and normalizes every postal address in your campaign. Whether you’re mailing to a single domestic address or thousands of international addresses, our Direct Mail Automation ensures each one is correct before printing.

Mastering Your Postal Address for Faster, More Reliable Delivery

Getting the postal address right is more than a formality—it’s the foundation for fast, error-free mail delivery. Whether you’re sending a domestic address postcard, an apartment address invoice, a business address proposal, or an international address package, following the correct address format ensures your mail arrives on time and at the right destination.

From placing the apartment number correctly to knowing when to use a po box address instead of a physical address, every detail matters. Add in special considerations for military addresses, international destinations, and country-specific formats, and it’s easy to see why so many shipments end up delayed or returned.

The good news? You don’t have to manage it all manually. With LettrLabs, you can automate address verification, format correction, and even full-scale campaign mailing—whether you’re targeting local customers or leads in multiple countries. Our platform integrates with your existing tools, provides real-time tracking and analytics, and supports a wide range of direct mail formats to match your campaign goals.

💡 Stop losing time and money on undeliverable mail. Discover how LettrLabs can handle your entire process—from verified mailing address data to on-time mail delivered—with our Direct Mail Automation and Tracking & Analytics Tools.