How to Type an Address on a Letter

The standard format for a typed address

A typed address on a letter follows a specific layout that postal services recognize and sort by machine. The address goes on the front of the envelope, in the lower right half, starting about one inch from the left edge and one inch from the bottom. Each line of the address should be left-aligned, single-spaced, and use a standard font like Arial or Times New Roman in 10 to 12 point size.

The order matters: recipient name on the first line, street address on the second, and city, state, and ZIP code on the third. Do not use punctuation at the end of lines. The USPS (United States Postal Service) reads addresses from bottom to top, so the ZIP code is what it scans first — getting that right matters more than perfect formatting elsewhere.

Key Takeaways

Type the recipient's full name on the first line, the street address on the second line, and the city, state, and ZIP code on the third line, with no punctuation at the end of any line.
Use all capital letters for the city and state abbreviation (for example, CHICAGO, IL) because postal machines read capitals more reliably than mixed case.
Place the address in the lower right half of the envelope, starting about one inch from the left edge and one inch from the bottom.
Leave the upper left corner of the envelope clear for your return address, which follows the same three-line format.
If you are mailing to an apartment or suite, put the unit number on the same line as the street address, after the street number and name.

Line-by-line breakdown of what goes where

Line 1: Recipient name. Type the full name of the person or business receiving the letter. If it is a business, use the official business name. If you are mailing to a specific person at a business, put their name first, then the business name on the next line (though this pushes the address to four lines, which is still acceptable).

Line 2: Street address. Type the street number, street name, and street type (Street, Avenue, Boulevard, Road, Drive, Court, Lane, etc.). If there is an apartment, suite, or unit number, add it after the street address on the same line — for example, "456 Oak Street Apt 12B" or "789 Commerce Drive Suite 300". Do not abbreviate the street type (do not write "St" instead of "Street").

Line 3: City, state, ZIP. Type the city name, then two spaces, then the two-letter state abbreviation, then two spaces, then the five-digit ZIP code. Use all capitals for both the city and state abbreviation. For example: "DENVER CO 80202" or "NEW YORK NY 10001". If you have a nine-digit ZIP code (ZIP+4), add a hyphen and the four digits after the five-digit code — "80202-1234".

Return address placement and format

Your return address goes in the upper left corner of the envelope, using the same three-line format as the recipient address. Start about half an inch from the top and half an inch from the left edge. Use a smaller font size than the recipient address — 10 point is standard — so the postal machine knows which is which.

If you are mailing from a business, the return address is the business address. If you are mailing from home, use your home address. The return address helps the post office send the letter back to you if delivery fails. Some people skip the return address on personal mail, but including it is safer.

Capitalization and punctuation rules

Use all capital letters for the city and state line. This is not a style choice — postal machines read capitals more reliably than mixed case, and using capitals speeds up sorting. The recipient name and street address can be in regular capitalization (capital letter at the start of each word), but capitals work there too.

Do not use any punctuation at the end of lines. No periods, no commas, no apostrophes in contractions. Punctuation slows down machine reading and can cause sorting errors. The only punctuation that belongs on an address is the hyphen in a ZIP+4 code.

Common mistakes that slow delivery

The most common error is abbreviating the street type — writing "123 Main St" instead of "123 Main Street". Postal machines do not always recognize abbreviations, and a letter may be delayed while a human sorts it manually. Similarly, abbreviating the state name (like "Colo" instead of "CO") causes delays.

Another frequent mistake is using lowercase letters on the city and state line. Machines read capitals faster, and mixing cases can trigger a manual sort. Leaving out the ZIP code or using an incorrect one is also common and causes the longest delays — the post office may have to look up the correct code, or the letter may be sent to the wrong location first.

Do not use special characters or accents in the address, even if the recipient's name contains them. Type "Jose" instead of "José", and "Sao Paulo" instead of "São Paulo". Postal machines in the US do not read accented characters reliably.

Typing an address for an apartment or PO box

For an apartment, condo, or townhouse, put the unit number on the same line as the street address. Write it after the street name and before the city line — for example, "456 Oak Street Apt 12B" on line 2, then the city and state on line 3. Some addresses use "Unit", "Suite", or "#" instead of "Apt"; any of these works.

For a PO box, the format is slightly different. Line 1 is the recipient name, line 2 is "PO Box" followed by the box number (for example, "PO Box 5678"), and line 3 is the city, state, and ZIP. Do not include a street address when mailing to a PO box — the box number replaces it.

International addresses and special cases

If you are mailing to Canada, Mexico, or another country, the format changes. The recipient's country name goes on the last line, in all capitals. For Canada, the postal code format is different (it uses letters and numbers in a specific pattern). For other countries, follow the postal format of that country, but always end with the country name in capitals on the final line.

If you are mailing to a military address (APO or FPO), the format is similar to a domestic address, but the "state" is replaced with "AP" (Armed Forces Pacific), "AE" (Armed Forces Europe), or "AA" (Armed Forces Americas), and the ZIP code is a military postal code. The USPS website has a full guide to military addresses if you need it.

Frequently Asked Questions

Can I type the address in lowercase letters?

You can, but it is not recommended. Postal machines read capital letters faster and more accurately. If you type the city and state in lowercase, the letter may be delayed while a human sorts it manually. Using all capitals on the city and state line is the safest choice.

What if the street address is very long?

If the street name or unit number is long, keep it on one line if it fits. If it does not fit, you can move the unit number to its own line — so the street address is on line 2 and the unit number is on line 3, with the city and state on line 4. This is acceptable to the USPS.

Do I need to include the ZIP+4 code?

The five-digit ZIP code is all that is required. The ZIP+4 (the additional four digits) is optional but helpful — it narrows the delivery area and can speed up sorting. If you have it, include it. If you do not, the five-digit code alone is fine.

What font should I use?

Any standard, readable font works — Arial, Times New Roman, Calibri, or Courier. Avoid decorative or script fonts; postal machines need to read the letters clearly. Use 10 to 12 point size for the recipient address and 10 point for the return address.

Can I print the address directly on the envelope?

Yes. Most printers can print directly onto envelopes. Set your printer to envelope size, position the address in the lower right half of the page, and print. Make sure the address is at least one inch from the bottom and left edges of the envelope so postal machines can read it without obstruction.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.