How to Mail a Letter: Every Step, From Envelope to Drop-Off

You've got a sealed birthday card, a rent check, or a form the DMV insists on receiving by mail. Learning how to mail a letter comes down to three marks on the envelope and one decision about where to drop it. Return address top-left, recipient's address in the center, stamp top-right. That's the whole shape of it, and the rest of this guide fills in the parts that actually trip people up: how many stamps, what it costs right now, and the odd situations like apartments and PO Boxes that no quick tutorial bothers to explain.

Mail a Letter in Six Steps

To mail a standard letter inside the U.S., follow this order:

1. Put your letter in an envelope and fold it to fit.
2. Write your return address in the top-left corner.
3. Write the recipient's full address in the center.
4. Stick one Forever stamp in the top-right corner (for a 1-ounce letter).
5. Seal the flap completely.
6. Drop it in your home mailbox with the flag up, a blue USPS collection box, or hand it to a clerk.

USPS confirms this basic layout and drop-off flow on its official letters page. Everything below is the "wait, but what about…" version.

Here's the envelope, roughly:

```

[Your address]

top-left [stamp]

top-right

[Recipient's name]

[Street address]

[City, State ZIP]

center

```

Return Address Top-Left

Write your own name and address in the top-left corner. Small, neat, out of the way. This is the address the Postal Service uses if the letter can't be delivered — wrong ZIP, moved recipient, torn envelope. Skip it and a return-to-sender letter has nowhere to go. First-Class mail with no valid return address and no deliverable address ends up at a USPS mail recovery center, where it may be opened to find a clue or, eventually, destroyed.

So the return address isn't decoration. It's your insurance policy. If you want the full breakdown of spacing, punctuation, and the mistakes that cause misreads, our guide on how to address an envelope walks through both corners in detail.

Recipient's Address in the Center

The center of the envelope holds the delivery address, and this is the part the sorting machines read. Four lines, usually: name, street number and street (or PO Box), then city, state, and ZIP on the bottom line.

Print it. Cursive slows down the optical scanners, and a machine that can't read your envelope hands it to a human, which adds a day or two. Use the two-letter state abbreviation (NY, not New York) and the full ZIP if you have it. Sending to a business or a specific person inside one? Add their name on the top line and the company on the second.

One quiet rule people miss: a PO Box and a street address don't belong on the same envelope. Pick the one the recipient actually uses. If both appear, USPS delivers to whichever line sits directly above the city-state-ZIP line, so put the correct one there.

Choose the Right Postage

Now the question every quick guide skips. One stamp or two?

A standard letter needs a single Forever stamp if it meets all three of these: it weighs 1 ounce or less, it's rectangular, and it's no bigger than 11-1/2 by 6-1/8 inches. Roughly, that's a normal envelope with up to about four or five sheets of regular paper inside. Cross an ounce and you owe extra postage. Cross into a square envelope, a stiff invitation, or something lumpy, and USPS charges a non-machinable surcharge even if it's light.

As of mid-2025 the Forever stamp costs $0.78, with additional-ounce postage priced separately. Rates change, so confirm the current figure on usps.com before you buy in bulk. The nice thing about Forever stamps is right there in the name — a stamp you bought at $0.68 still covers a 1-ounce letter after a price increase, no math required.

That's exactly why they're worth keeping a book of at home. We stock authentic first class stamps sourced from closed businesses and inspected for unused, unbent condition, so you're not overpaying at the counter or hunting for a post office at 8 p.m.

When to use two stamps: a letter running 1 to 2 ounces, a chunky greeting card, or several folded pages. If you're unsure and the item feels heavy, weigh it on a kitchen scale or ask a clerk. Guessing low means it comes back for postage; guessing high just wastes a few cents.

Seal It and Send It

Lick it, wet it, or press the self-adhesive strip — whatever your envelope uses, close the flap all the way. A half-sealed corner can snag in the machines and spill the contents.

Then choose a drop-off. You have three easy ones:

• Your home mailbox. Put the letter inside and raise the red flag. Your carrier collects outgoing mail on the next visit.
• A blue USPS collection box. Curbside boxes on street corners. Check the pickup time printed on the door if you're mailing something time-sensitive late in the day.
• The post office counter. Hand it to a clerk. Best when you need to weigh the letter, buy postage, or send anything requiring a receipt.

Not sure where the nearest one is? The USPS location finder maps post offices and collection boxes by ZIP. First-Class letters typically move in 2 to 5 business days (USPS Blog), though service standards shift, so treat that as a window and not a promise.

Apartments, PO Boxes, and Beyond

The standard steps assume you have a mailbox with a flag. Plenty of readers don't.

From an apartment. No personal flag? You've got options. Most buildings have an outgoing-mail slot in the lobby mailbox bank — a small door labeled for letters going out. Drop it there and the carrier grabs it during delivery. No slot? Walk it to the nearest blue box or the post office. Never leave a stamped letter loose on top of the mailboxes hoping the carrier notices; that's a coin flip.

To a PO Box. Address it exactly as the recipient wrote it: name, then "PO Box" and the number, then city, state, ZIP. No street address needed. Postage is identical to any other letter.

To the DMV or a government agency. Ordinary First-Class works, but for anything with a deadline or legal weight — a title transfer, a court filing, a signed form — consider Certified Mail with return receipt. You get a tracking number and proof of delivery, which matters when an agency claims it never arrived. Ask for it at the counter.

Internationally. This isn't the same as domestic mail with extra postage. You'll need international postage (a Global Forever stamp covers a 1-ounce letter to any country), the recipient's address in the format that country uses, and the destination country's name in capital letters on the bottom line. Anything beyond a flat letter usually needs a customs form. For heavier or faster shipments, look at priority mail stamps instead of trying to stack letter postage.

Without leaving home. Beyond raising your mailbox flag, you can print postage at home through USPS Click-N-Ship or third-party services, or use an online print-and-mail service that prints and sends the letter for you. Handy for a one-off when you're out of stamps, though for regular letters, a book of Forever stamps in a drawer is cheaper and faster.

FAQ

How do you properly mail a letter?

Seal your letter in an envelope, write your return address top-left and the recipient's address in the center, add a Forever stamp in the top-right corner, then drop it in a mailbox, blue collection box, or at the post office.

How do I know if I need 1 or 2 stamps?

One Forever stamp covers a rectangular letter up to 1 ounce (about four or five sheets of paper). Add a second stamp for letters between 1 and 2 ounces, or for stiff, square, or oversized envelopes.

How much is it to mail a letter at the Post Office?

A 1-ounce First-Class letter costs $0.78 with a Forever stamp as of mid-2025. Rates change periodically, so check usps.com for the current price before buying.

How do I mail a regular envelope?

Fold your letter inside a standard #10 envelope, add the two addresses and a stamp, seal it, and drop it off. A regular envelope needs no special handling as long as it's under 1 ounce and rectangular.

Once you've done it twice, mailing a letter stops feeling like a lost art and starts feeling like muscle memory. Keep a book of stamps on hand so the only step left is walking to the box. At Mailboxes of Flushing, we supply authentic, inspected Forever and first-class stamps at prices that beat the counter, shipped within 24 hours — so you're always ready for the next card, check, or form that has to go out today.