Addressing Envelope 101
US address format
A standard US address has three lines: the recipient name, the street address (with any apartment or suite number), and the city, state, and ZIP code, in that order. The state is written as its two-letter abbreviation, and USPS convention drops punctuation like commas and periods, though most delivery still works fine with them included.
Checked September 10, 2026/8 min read
Written by Claire PostReviewed against USPS Publication 28
What is on this page6 sections
A US address always reduces to the same three pieces, no matter what it is being written on: who it is for, where the building is, and which city, state, and ZIP that building sits in. Envelopes, shipping labels, and government forms each dress that structure up slightly differently, but the underlying order does not change.
Most of the confusion around US address format comes from context switching. The same person who correctly writes a three-line envelope address every year can still hesitate at a checkout form asking for “Address Line 1” and “Address Line 2,” because that split is a form convention, not a postal one.
Step by step
Line one is the recipient
A full name, or a business/organization name for a company address. This line identifies who the mail or shipment is for, separate from where it is going.
Line two is the street address
House or building number, street name, and any directional (N, SW, and so on). If there is an apartment, suite, or unit number, it goes at the end of this same line whenever it fits, not on a line by itself.
MORGAN LEE512 W CHESTNUT ST APT 3BOISE ID 83702CorrectA standard three-line address, unit number included on the street line. A separate line two is the exception, not the default
Some forms and shipping platforms split "Address Line 1" and "Address Line 2" into two input fields, with Line 2 reserved for the apartment, suite, or building detail. That is a form-field convention, not a USPS rule, and it only applies when the platform itself asks for it that way.
The last line is city, state, and ZIP, in that order
The state is written as its two-letter postal abbreviation, never spelled out or written any other way. The ZIP code follows the state with one space, no comma.
BOISE ID 83702CorrectThe last line, formatted the way USPS scanning equipment expects. Skip punctuation, but do not worry if you cannot
USPS standardized format drops commas and periods entirely. Mail addressed with a comma after the city, or a period after the state abbreviation, still gets delivered correctly. The punctuation-free version is the equipment-preferred standard, not a requirement for delivery.
Quick reference
| Line | Contents | Example |
|---|---|---|
| 1 | Recipient name or business name | MORGAN LEE |
| 2 | Street address, unit number included if it fits | 512 W CHESTNUT ST APT 3 |
| 3 | City, state (two-letter), ZIP code | BOISE ID 83702 |
Special cases
The rule above covers most people. Here is what changes for the rest.
Does the address format change for a business versus a personal address?
The three-line structure stays the same. A business address typically adds the company name as its own line above the street address, giving it four lines instead of three, but the street and last-line rules do not change.
What if the street address will not fit on one line with the unit number?
The unit number moves to its own line directly above the street line, never below it. The line immediately above the city/state/ZIP line is always read as the delivery line, so nothing that matters should sit below the street address — see <a href="/how-to-address-envelope-apartment/">addressing an envelope to an apartment</a> for that placement rule in full.
Does a PO Box follow the same three-line format?
Yes, with the PO Box number replacing the street address on line two. If both a street address and a PO Box are listed for the same recipient, USPS delivers to whichever one appears on the last line before the city/state/ZIP — see <a href="/how-to-address-envelope-po-box/">addressing an envelope to a PO Box</a> for the full format.
Key terms on this page
- Standardized address
- The USPS-preferred format for a deliverable address: recipient, street line, then city/state/ZIP, using standard abbreviations and no punctuation.
- Delivery line
- The line directly above the city, state, and ZIP line. This is the line USPS equipment and carriers read to actually route the mail.
- Two-letter state abbreviation
- The official USPS postal abbreviation for a state, used in place of the full state name on the last line of a standardized address.