How to Address an Envelope in the USA

An envelope has three blocks of information, and USPS sorting equipment reads them in fixed places: your return address in the top-left corner, the recipient’s delivery address in the center, and postage in the top-right corner. Get the format below right and your letter moves through automated processing without a human ever squinting at it.

The Delivery Address (Center of the Envelope)

Write or print the recipient’s address in the center of the envelope, in this order:

JANE DOE
1234 MAIN ST APT 5B
SPRINGFIELD IL 62704

• Line 1: the recipient’s full name (or company name).
• Line 2: street number and street name, with the apartment or suite number on the same line, after the street address. (If it truly will not fit, USPS puts the secondary unit on the line directly above the street line — never below it.)
• Line 3: city, two-letter state abbreviation, and ZIP Code — ZIP+4 whenever you know it.

For a PO Box, replace the street line with PO BOX and the number. For a business, the company name can go above the person’s name, or add an ATTN line above the name if a specific person must receive it.

The Return Address (Top-Left Corner)

Same format, smaller footprint, in the upper-left corner of the same side of the envelope:

JOHN SMITH
5678 OAK AVE
DENVER CO 80202

USPS recommends always using a return address. If the letter cannot be delivered, the return address is the only way it comes back to you instead of being destroyed. It is formally required on some categories of mail (for example, mail paid with a permit imprint or precanceled stamps), and it costs you nothing to include on everything else.

Formatting Rules USPS Actually Publishes

These come from USPS addressing guidance and its “How to Send a Letter” instructions:

• Print neatly in capital letters; dark ink on a light envelope.
• No commas or periods in the address block. Punctuation adds nothing for the machines and is omitted in the USPS standard format.
• Use USPS abbreviations for street suffixes and units — ST, AVE, BLVD, APT, STE — and two-letter state abbreviations.
• Include directionals where they are part of the address (N, S, E, W, and combinations like NW). In many cities the directional is the difference between two different streets.
• Left-align the block, keep lines parallel to the bottom edge of the envelope, and keep the bottom margin clear — that strip is where USPS prints its processing barcode.
• Use the ZIP+4 code when you can; the five-digit ZIP alone is acceptable. Never guess a ZIP Code — USPS guidance is blunt on this point: no ZIP is better than a wrong ZIP, because a wrong one actively routes the letter to the wrong place.

Where the Stamp Goes

Postage belongs in the top-right corner of the same side as the addresses. If you are mailing something that needs extra postage — a heavy letter or a square card — the additional stamps go right beside it in that same corner area. What counts as “extra” is covered in USPS letter size and weight requirements.

Special Cases Worth Knowing

Apartments and suites

The unit number is part of the delivery address, not an optional detail. A large share of undeliverable personal mail is missing exactly this. If you are unsure whether someone is in Apartment 4B or 4D, ask them — do not average.

Rural and highway addresses

Rural route addresses use the format RR 2 BOX 123; highway contract routes use HC. These are current, valid USPS formats — copy them exactly as the recipient gives them rather than “correcting” them into street addresses.

Military mail (APO/FPO/DPO)

Military addresses use the service member’s name, a unit/box designation, APO (or FPO/DPO), the pseudo-state code AE, AP, or AA, and a ZIP Code — and must not include a real city or country name. The format is specific enough that if you mail to service members regularly, confirm the current USPS military addressing example before printing labels.

International mail

Add the destination country name, in English and in capital letters, as the last line of the address — and omit the ZIP-style codes rules vary by country. Nothing else about the layout changes.

Three Complete Examples, Annotated

A business delivery with a suite number. The ATTN line goes above the company name, and the suite rides on the street line:

ATTN MARIA LOPEZ
RIVERBEND ACCOUNTING LLC
410 COMMERCE ST STE 900
AUSTIN TX 78701

A PO Box delivery. There is no street line at all — the box number replaces it, and the ZIP Code is the one assigned to the box section, which may differ from the street ZIP for the same town:

THOMAS BECKER
PO BOX 1184
BURLINGTON VT 05402

An international delivery. The layout is identical, with the destination country in capital letters as the final line. A 1-ounce letter to another country currently mails with one Global Forever stamp, priced at $1.75:

EMMA WILSON
14 CHAPEL HILL
LONDON NW3 2JQ
UNITED KINGDOM

Three Atlanta Addresses, Annotated

The same rules, on the streets this site is edited from. (Names are illustrative; the formats are the point.)

A Midtown apartment. The unit rides on the street line, and the directional is not decoration — Atlanta has a Peachtree Street, a Peachtree Road, and a West Peachtree Street, and they are three different streets:

DANIEL KIM
855 PEACHTREE ST NE APT 1402
ATLANTA GA 30308

A Decatur house. A directional prefix and a spelled-out avenue name, exactly as the standard handles any city:

SARAH JOHNSON
415 E PONCE DE LEON AVE
DECATUR GA 30030

A Sandy Springs office. The suite goes on the street line after the street address; note that many Sandy Springs addresses use ATLANTA as the USPS city name with the 30328 ZIP Code — copy the city and ZIP as your recipient gives them, not as the map app prefers:

ATTN OFFICE MANAGER
NORTHSIDE DENTAL GROUP
1100 ABERNATHY RD NE STE 200
ATLANTA GA 30328

And the return address this editor puts in the top-left corner of his own holiday cards, in the same format:

JAMES MILLER
1234 PEACHTREE ST NE
ATLANTA GA 30309

In my years in commercial mail, Atlanta addresses taught one lesson better than any other city I worked with: copy the suffix and the directional exactly as given. On Peachtree, “close enough” is a different street, a different ZIP Code, and a card that comes back to you in January.

Handwritten or Printed?

Either is acceptable if it is legible. Printed labels are the safer choice for bulk mail and for anyone whose handwriting leans decorative. Handwriting is traditional for personal cards and works fine when it is dark, upright, and unhurried. What fails is contrast: light ink on a colored envelope, glitter pens, and script fonts at small sizes. If you are hand-addressing holiday cards at volume, the etiquette and presentation side is covered in how to address Christmas cards properly.

Common Addressing Mistakes That Delay Mail

• Guessing the ZIP Code. The costliest small error: a wrong ZIP actively routes the piece to the wrong facility, while a missing ZIP can still be resolved from the city and street. Look it up or leave it off — never invent it.
• Putting the apartment number in the wrong place. The unit belongs on the street line (or the line directly above it), never below the city line, where sorting equipment does not look for it. Missing units are a leading cause of undeliverable mail.
• Turning the address sideways. If the address block runs parallel to the envelope’s short side, the piece is treated as nonmachinable and picks up the $0.49 surcharge — the orientation rules are covered in USPS letter size and weight requirements.
• Writing over the bottom strip. USPS prints its processing barcode along the bottom edge. Artwork, seals, or a low-slung address block in that zone interferes with the machinery that sorts your letter.
• Low-contrast presentation. Light ink, metallic pens, and busy envelope patterns behind the address all force manual handling. Dark print on a plain light envelope is the fast lane.

A 10-Second Pre-Mail Check

1. Recipient name spelled the way they spell it?
2. Apartment/suite included?
3. City, state abbreviation, ZIP all present and correct?
4. Return address in the top-left?
5. Postage in the top-right, enough for the weight and shape?

Frequently Asked Questions

Can I put the return address on the back flap instead?

Personal mail often does, and it is a long-standing convention on formal stationery. The USPS standard placement, though, is the upper-left corner of the front — that is where sorting equipment and carriers look for it. For anything you genuinely need back if it fails (checks, documents, a business mailing), use the front; save the back flap for purely social cards.

Do I need the ZIP+4 code?

No. The five-digit ZIP Code is sufficient, and a correct five digits beats a guessed +4 every time. The extra four digits identify a specific delivery segment — a block, a building, one side of a street — and speed sorting when they are right. Look them up in the USPS ZIP Code tool if you mail to the same addresses repeatedly; otherwise, five digits and a clean address will do the job.

Is it a problem if I handwrite the address in lowercase, with commas?

Readable mail gets delivered, and carriers read ordinary handwriting all day. The capital-letter, no-punctuation format is the USPS standard because machines read it fastest, not because other formats are refused. If your handwriting is neat, it will travel fine; if you are addressing more than a handful of pieces, printed labels in the standard format remove the risk entirely.

More envelope rules and postage questions are collected in our USPS Mailing Rules hub, including what to do when a greeting card may need extra postage.

Sources

The rates, dates, and rules in this guide were checked against these official USPS pages:

• USPS: Letters
• USPS: Addressing Mailpieces

Related Guides

• USPS Mailing Rules hub — addressing, sizes, surcharges, and large envelopes in one place.
• How to address Christmas cards properly — the etiquette layer: couples, families, and titles on the envelope.
• USPS letter size and weight requirements — the size and weight window your addressed envelope still has to fit.
• Do greeting cards need extra postage? — when a correctly addressed card still needs more than one stamp.