How to Write an Address on a Postcard: 6 Steps

To write an address on a postcard, turn it to the back and use the right half: the recipient’s name on the first line, the street address (with any apartment or unit number) on the second, and the city, two-letter state abbreviation and ZIP Code on the last line. Put the stamp in the top-right corner, write your message on the left half, and keep the bottom 5/8 inch blank so USPS can print its barcode.

That’s the whole job for most postcards. The steps below add the details USPS machines look for, plus how to handle PO Boxes, apartments, return addresses and international postcards.

How Do You Write an Address on a Postcard, Step by Step?

1. Find the address side. Most postcards have a picture on the front and a back split by a vertical line. The left part is for your message; the right part is for the address and stamp. USPS says to write the delivery address in the space the card gives you, on the same side as your message and stamp.
2. Line 1: the recipient’s name. Use the full name the person receives mail under.
3. Line 2: the delivery address. Write the house number, street name and suffix, followed by the apartment, suite or unit on the same line (for example, 1234 OAK ST APT 5B).
4. Line 3: city, state and ZIP Code. Use the two-letter state abbreviation and, if you know it, the ZIP+4.
5. Add the stamp in the upper-right corner of the address side.
6. Optional: add your return address in the upper-left corner of the address area, or at the top of the address section if the card has no room.

Here’s what a finished postcard address looks like:

SARAH JOHNSON
1234 OAK ST APT 5B
PORTLAND OR 97205-1234

Where Exactly Does the Address Go on a Postcard?

The address goes on the right half of the back, low enough for USPS scanners to read it. The Domestic Mail Manual (DMM 202.2.1) puts the optical character reader (OCR) read area between 5/8 inch and 2-3/4 inches from the bottom edge, and at least 1/2 inch in from the left and right edges.

Below that, the barcode clear zone (DMM 202.5.1) covers the bottom 5/8 inch of the card across the rightmost 4-3/4 inches. USPS prints a barcode there during processing, so leave it free of writing, stickers and artwork.

For more on how USPS reads and sorts mail, the USPS shipping guide to services and tracking is a good starting point.

How Should You Format the Postcard Address So USPS Can Read It?

USPS Publication 28 asks for a complete, standardized address with a uniform left margin and prefers uppercase letters. Handwritten lowercase is fine as long as it’s clear, but printing in capitals is easiest for machines to read.

• Use dark ink (black or blue) on a light background, never pencil.
• Use the standard abbreviations USPS lists (ST, AVE, BLVD, APT, and two-letter state codes).
• Keep the apartment or unit number on the street line, not on a separate line under the city.
• Look up a ZIP+4 with the USPS ZIP Code lookup if you’re unsure of the ZIP.
• Don’t add anything below the city, state and ZIP line, because USPS reads that line as the destination.

Small errors, like a missing apartment number, are the usual reason mail goes to the wrong door. The same is true for packages, as the guide to what to do when UPS delivers to the wrong address shows.

How Do You Address a Postcard to a PO Box or Apartment?

For a PO Box, replace the street line with the box number: name, then PO BOX 123, then city, state and ZIP. Don’t write both a street address and a PO Box on the card, because USPS delivers to whichever address is on the line just above the city, state and ZIP. Our guide on how to send mail to a PO Box covers the edge cases.

For an apartment, condo or suite, put the unit designator and number at the end of the street line, such as 500 MAIN ST UNIT 12. If it doesn’t fit, USPS accepts the unit on the line directly above the street line.

For a private mailbox at a pack-and-ship store, include the “PMB” or “#” box number, which USPS requires for mail to a commercial mail receiving agency.

Do Postcards Need a Return Address?

No. USPS doesn’t require a return address on a stamped First-Class Mail postcard; it’s required only on certain mail types, such as packages and mail with extra services. The details are in our guide on whether you can mail something without a return address.

A return address is still a good idea if the card matters to you, because without one an undeliverable postcard can’t come back. If you’d rather not write your home address, see how to ship without using your home address for PO Box and private mailbox options.

What Size Does a Postcard Have to Be?

To mail at the postcard price, a card must be rectangular, 3-1/2 to 4-1/4 inches high, 5 to 6 inches long, and 0.007 to 0.016 inch thick, according to USPS. Its length divided by its height must fall between 1.3 and 2.5 (DMM 201).

Larger or square cards are mailed as letters and cost more. The guide to postcard stamps and how many you need explains which stamp to use for standard and oversized cards.

How Do You Address an International Postcard?

Write the address the way the destination country formats it, then add the country name in capital letters on its own line at the bottom, in English. Many countries put the postal code before the city or use a different line order, so check the format first, for example the UK address format.

International postcards need international postage (a Global Forever stamp covers a standard postcard). The address side layout is the same: message on the left, address and stamp on the right.

What Happens If a Postcard Is Addressed Incorrectly?

If USPS can’t deliver a postcard and there’s a return address, it’s returned to you, usually with an endorsement explaining why. With no return address, it becomes undeliverable mail and may be discarded or sent to the Mail Recovery Center.

If the recipient moved, mail forwarding may still get it there. Here’s how USPS forwarding options work. Postcards can’t be tracked, so if a card never arrives the only recourse is a Missing Mail search, the same process used to report a lost USPS package.

Frequently Asked Questions

Which side of a postcard do you write the address on?

Write the address on the back of the postcard, the side without the picture, in the right half. The left half is for your message and the top-right corner is for the stamp. USPS says to write the delivery address in the space the card provides, on the same side as the message and stamp, and to keep the bottom 5/8 inch clear for its barcode.

How do you write an address on a postcard with an apartment number?

Put the apartment number at the end of the street line, for example 1234 OAK ST APT 5B, with the recipient’s name above it and the city, state and ZIP Code below it. If the unit won’t fit on the street line, USPS accepts it on the line directly above. Never put it under the city, state and ZIP line.

Do you need a return address on a postcard?

No. USPS delivers stamped First-Class Mail postcards without a return address, because the Domestic Mail Manual requires one only on certain mail types, such as packages and pieces with extra services. Adding one in the upper-left corner of the address side is still recommended, since an undeliverable postcard without a return address can’t be sent back to you.

How do you address a postcard to another country?

Write the recipient’s address in the destination country’s format, then put the country name in capital letters on the last line, in English. Keep the message on the left and the address and stamp on the right, as for a domestic card. A Global Forever stamp covers postage for a standard-size postcard to any country USPS serves.

Sources

• USPS: Send Letters, Postcards and Large Envelopes
• USPS Domestic Mail Manual 201: Physical Standards for Cards and Letters (1.2)
• USPS Domestic Mail Manual 202: OCR read area and barcode clear zone (2.1, 5.1)
• USPS Domestic Mail Manual 602: Addressing (return addresses, PMB addresses)
• USPS Publication 28: Postal Addressing Standards (sections 211–212)
• USPS ZIP Code Lookup

Part of our Best Way to Mail Important Documents guide. Related: Can I Ship Tax Documents to the Irs, Precious Metal Shipping, What Is the Best Way to Send a Passport.