Write the recipient address centered on the front (no commas), your return address top-left, and the stamp top-right. Use dark ink or a permanent marker on a light background, print clearly, and omit punctuation from the address block except the ZIP+4 hyphen when used.
Before you start
- Format: no commas between city and state, no periods after abbreviations
- Military mail: use APO/FPO/DPO plus AA/AE/AP — never write the foreign country name
- Return address: without it, undeliverable mail goes to the Mail Recovery Center
The USPS moves hundreds of millions of mail pieces a day, and almost none of them are read by a human first — high-speed cameras and OCR software do the sorting.
Keep the delivery address within the USPS optical-character-reader area and print it clearly. Poor placement or contrast can make automated processing harder and may lead to additional handling or delay. Leave off the return address and an undeliverable letter ends up at the Mail Recovery Center in Atlanta instead of coming back to you.
USPS Publication 28 says punctuation may be omitted from the delivery address block, except for the hyphen in a ZIP+4 code when used. Clear, consistent formatting supports automated processing.
How to format the address block
Four lines, machine-friendly habits — this is the layout USPS automation expects:
Standard Envelope Formatting
1. Recipient Name
JOHN SMITH (Use all capital letters if possible). If mailing to a business, place the company name on the line above the person’s name, or use “ATTN: JOHN SMITH”.
2. Street Address
1234 MAIN ST APT 4B. Always put the apartment or suite number on the same line as the street address. If it doesn’t fit, put it on the line above the street address.
3. City, State, ZIP
ANYTOWN NY 12345. Use the official two-letter state abbreviation (e.g., NY, TX, CA). Leave one full space between the state and the ZIP code.
4. The ZIP+4 Code
Using the 9-digit ZIP code (e.g., 12345-6789) is optional, but it directs the mail to the exact street segment, speeding up delivery by skipping one sorting phase.
Special Formatting: Military and International Mail
If you are mailing a letter overseas, the rules change drastically.
Specialty Mailing Matrix
Step-by-Step Guide to Formatting
Same layout whether it’s a birthday card or a dispute letter with a deadline — the three steps below cover both:
Step 1: Write the Delivery Address
Use dark ink or a permanent marker on a light background. Avoid pencil and print clearly; USPS readability guidance emphasizes contrast, spacing, and legibility rather than a single required ink color. Write the recipient’s information exactly in the center. Keep all lines left-justified (aligned evenly on the left side).
Step 2: Write the Return Address
Write your own address in the top-left corner. Write it much smaller than the delivery address so the scanner does not get confused about which address to send it to.
Step 3: Affix the Postage
Place a Forever Stamp in the top right corner. If the envelope weighs more than 1 ounce (about 4 sheets of paper), you will need to add extra postage (an “Additional Ounce” stamp). If you don’t, the letter will be returned to you for insufficient postage.
For anything deadline-driven — dispute letters, legal notices, applications — copy this layout so it clears OCR on the first pass:
456 OAK LN APT 12
SPRINGFIELD IL 62704
STAMP
HERE
ACME CORPORATION
1234 BUSINESS PKWY STE 200
NEW YORK NY 10001-1234
Common Myths vs. USPS Realities
People often decorate envelopes in ways that actively sabotage the delivery process.
4-Stage USPS Automated Processing Roadmap
Stage 1: Optical Character Reader (OCR) Scanning
High-speed cameras photograph the envelope face, scan the recipient address block, and verify the delivery ZIP+4 code in national directory databases.
Stage 2: Barcode Printing & Facing Identification
An Intelligent Mail barcode (IMb) is sprayed into the bottom 5/8-inch clear zone, encoding route sorting, mail class, and unique tracking serial numbers.
Stage 3: Regional Distribution Center Sorting
Automated barcode sorters route the letter into designated dispatch bins corresponding to airport air cargo or ground surface logistics networks.
Stage 4: Delivery Point Sequence (DPS) Carrier Walk
At the local destination station, DPS machines sort letters in exact sequential delivery walk order for the local postal carrier.
Myth vs. Fact
“Writing ‘FRAGILE’ or ‘DO NOT BEND’ on the envelope means the mail carrier has to treat it gently.”
Writing these words does absolutely nothing. The sorting machines cannot read them. If you don’t want a photo or document bent, you must place a stiff piece of cardboard inside the envelope and pay the ‘Non-Machinable Surcharge.’
“Using a wax seal makes the letter look professional and secure.”
Wax seals and other rigid or raised decorations can interfere with automated processing. If you use one, take the piece to a post office counter and ask whether it requires extra packaging, a nonmachinable surcharge, or another mailing service.
Frequently Asked Questions
Can I tape a stamp on so it doesn’t fall off?
Use postage as directed by USPS and keep the stamp or postage area clear of tape, markings, and other material that could interfere with processing. For a loose stamp, replace it rather than relying on tape; if the item is unusual or valuable, ask a clerk for the correct mailing method.
What does “c/o” mean on an envelope?
Care of. Use it when the recipient is at an address that isn’t their own: JOHN SMITH, c/o ACME LAW FIRM, then the street address. The mail still goes to the address — c/o just tells the household or business who the letter is for.
Where does the certified or tracking sticker go?
Flat along the top edge of the envelope, to the left of the postage, with room for the postmark. Don’t wrap it around an edge — the barcode has to stay on one plane for the scanner.
What happens to mail with no return address?
If it can’t be delivered, there’s nowhere to send it back. Undeliverable non-returnable mail goes to the USPS Mail Recovery Center and is eventually auctioned or destroyed. One line in the top-left corner buys you the safety net.
HowMira is an independent educational site – not the USPS. We cannot track your mail or find lost letters. File a Missing Mail Search directly on USPS.com.
If mail goes missing
Work in this order: check the tracking or certified-mail receipt, allow 7 business days from mailing, then file a Missing Mail search on USPS.com with the envelope details. Stolen checks or washed mail go to the USPS Postal Inspectors. And send anything deadline-driven by certified mail — the receipt is your proof of the mailing date, the same rule that governs FCRA credit-report disputes.
HowMira is an independent educational site – not a government agency. We link to official .gov and .org sources, but we cannot file a complaint for you or give legal advice. Read our full Legal Disclaimer & Safe Harbor →