How to Address an Envelope: Proper Format and Examples

Learning how to address an envelope the right way takes about two minutes. Put your return address in the upper-left corner, the recipient’s address in the center, and the stamp in the upper-right corner. Machines sort nearly every letter, so clear, simple formatting gets your mail delivered faster.

This guide shows the exact envelope format the post office prefers, with placement rules, line-by-line examples, and fixes for tricky cases like apartments, businesses, PO boxes, and international mail. Follow the steps below and every envelope you send will look correct.

In this guide

1. The three-part envelope layout
2. Writing the delivery address line by line
3. Tricky cases: apartments, business, PO boxes, military, international
4. Stamps, ink, and mistakes to avoid
5. Quick comparison: envelope layouts
6. Frequently Asked Questions

The three-part envelope layout

• 1. Return address goes in the upper-left corner, Write your full name and address in the top-left corner of the envelope.
  Always include one. If the letter cannot be delivered, the post office sends it back to you instead of discarding it.
• 2. Delivery address goes in the center, The recipient’s name and address sit in the middle of the envelope, roughly centered both ways.
  Leave clear space around and below this block. Sorting machines need the empty zone to print routing barcodes.
• 3. The stamp goes in the upper-right corner, Postage always sits in the top-right corner, on the same side as the addresses.
  Keep stamps away from seams, tape, and wrinkles so scanners can read them cleanly.
• 4. Keep the bottom strip of the envelope clear, Leave the bottom 5/8 inch of the front free of any writing or decoration.
  Automated equipment prints barcodes there. Text in that strip can confuse the machines and delay your mail.
• 5. Turn the envelope so the long side is horizontal, Address the largest face of the envelope, with the longest edges along the top and bottom.
  This orientation is what every sorting machine expects, and it gives the address blocks their proper corners.

Writing the delivery address line by line

• 1. Recipient’s name on the first line, Write the full name of the person or family. For formal letters, add a title such as Mr., Mrs., or Dr.
  JANE A DOE
  or
  Mr. and Mrs. John Kelly for formal invitations
• 2. Street address on the second line, House number first, then the street name, written exactly as the recipient gave it.
  1234 MAIN ST
  Double-check the number. One wrong digit sends your letter to the wrong house.
• 3. Apartment or unit numbers go on the same line, Place the unit after the street address when it fits, such as “1234 MAIN ST APT 5B.”
  If it does not fit on one line, put the apartment number on the line directly above the street address.
• 4. Last line: city, state, and ZIP Code, Write the city, the two-letter state abbreviation, and the ZIP Code on the final line.
  CHICAGO IL 60601
  Add the ZIP+4 (60601-1234) if you know it, you can look it up free at zip4.usps.com.
• 5. Skip most punctuation in the address block, Postal standards prefer no commas between city and state and no periods after abbreviations.
  ALL CAPS is preferred for machine readability. Clear, high-contrast lettering matters more than perfect penmanship.

Tricky cases: apartments, business, PO boxes, military, international

• 1. Apartments, suites, and floors, Add APT, STE, or FLR after the street address on the same line.
  455 MARKET ST STE 800
  Never leave the unit off. Carriers cannot guess which of fifty doors is yours.
• 2. Business mail, Put the company name on the first line, then the department or person’s name on the second.
  ACME SUPPLY CO
  ATTN: ACCOUNTS PAYABLE
  789 INDUSTRIAL PKWY
  When you are unsure of the exact address, take a minute to research a company’s correct address before mailing.
• 3. PO boxes, A PO box replaces the street address entirely. Use one or the other, never both.
  PO BOX 1234
  DALLAS TX 75201
  Including both a street address and a PO box forces the carrier to guess where to deliver.
• 4. Military mail (APO, FPO, DPO), Use APO, FPO, or DPO with the AA, AE, or AP code in place of the state.
  SGT JOHN DOE
  UNIT 1234 BOX 5678
  APO AE 09321
  Never write the foreign country name on military mail, the APO system routes it for you.
• 5. International mail, Keep the same layout, but add the destination country in English, in all caps, on the last line.
  14 RUE DE LA PAIX
  75002 PARIS
  FRANCE
  Check the destination country’s own line order for its domestic addresses if you want to be extra safe.

Stamps, ink, and mistakes to avoid

• 1. Put the stamp only in the upper-right corner, That is the single correct spot. Postage anywhere else forces slow hand processing.
  Press the stamp down firmly. Loose stamps fall off during high-speed sorting and leave your letter unpaid.
• 2. Weigh anything heavy or oddly shaped, One Forever Stamp covers a standard one-ounce letter, but heavier or oversized mail needs more postage.
  Weigh the complete sealed envelope at the post office before buying stamps for a full batch of invitations.
• 3. Use blue or black ink only, Sorting cameras read dark ink on light paper best. Red, green, or pencil can fail to scan.
  Print clearly rather than using fancy cursive. Machines read plain block letters most reliably.
• 4. Write in ALL CAPS for the address block, Capital letters are the machine-preferred format for US delivery addresses.
  1234 MAIN ST APT 5B
  CHICAGO IL 60601
  You do not need perfect uppercase handwriting, just keep it large, dark, and legible.
• 5. Seal it flat and do a final check, Seal the envelope, confirm the stamp is stuck, and reread the address before mailing.
  A two-second review catches transposed ZIP digits and forgotten apartment numbers, the two most common causes of returned mail.

Quick comparison: envelope layouts

Frequently Asked Questions

Is a return address required on an envelope?

It is strongly recommended, and the post office requires it for certain mail classes and services. A return address lets undeliverable mail come back to you so you can fix the address and try again.

Where exactly does the stamp go on an envelope?

The stamp, or any printed postage, goes in the upper-right corner on the front of the envelope, the same side as the addresses. Placing it anywhere else means slower hand processing.

How do you address an envelope to a business?

Put the company name on the first line, then the department or person’s name on the second line, followed by the street address and the CITY ST ZIP line. Adding “ATTN:” before a department name routes the letter to the right desk.

Can I handwrite the address on an envelope?

Yes. Handwritten addresses work fine as long as they are clear, dark, and legible. Use blue or black ink, print in all caps, and skip decorative fonts that sorting cameras struggle to read.

How many stamps does a standard letter need?

A standard one-ounce letter needs one Forever Stamp. Anything heavier, thicker, or oddly shaped needs additional postage, weigh the sealed envelope at the post office first so you neither overpay nor underpay.

The golden rule of envelopes: top-left is from you, center is to them, top-right is the stamp. Everything else is detail.

Final thoughts

Addressing an envelope correctly is a small skill that prevents big headaches. Remember the three corners, return address top-left, recipient center, stamp top-right, write in clear all caps, keep the bottom strip empty, and double-check the ZIP Code before you seal it. For the official rules straight from the source, see this USPS guide to addressing your mail. Mailing to a long list of people? Clean up your mailing list in Excel first, and keep your mailroom plan on a clean whiteboard, every letter will arrive looking professional.