A self addressed stamped envelope, usually shortened to SASE, is a blank envelope you address to yourself and stamp in advance so someone else can mail something back to you. That is the whole of what is a self addressed stamped envelope, and the details are in the postage and the size. In 2026 a standard SASE holding up to 1 ounce needs one Forever stamp, which is worth $0.82.
You send the SASE inside a larger envelope, and the recipient drops the contents into it and mails it. You pay the return postage up front, and they only have to add the contents and seal the flap.
What is a self addressed stamped envelope used for?
The idea is simple: you cover the postage for the reply. That removes the cost and effort for the person answering, which makes them more likely to respond. Common uses include:
- Manuscript and query submissions. Many publishers and literary magazines that accept mail ask for a SASE so they can send back a response or your pages.
- Document returns. Agencies, clerks and licensing offices often mail back original certificates, titles or signed forms in the envelope you supply.
- Ticket and permit requests. Some small events, parks and clubs mail tickets, passes or stickers to a SASE.
- Autograph and fan mail. Collectors send a SASE with an item to be signed and returned.
- Letters to Santa. Some programs write back to children who include a stamped return envelope. See our guide on where to mail a letter to Santa for the details.
To the person replying, a SASE saves a trip and the cost of a stamp. That is why many offices expect one with a mailed request.
Always read the instructions from the person you are writing to. Some ask for a specific size, and some say they will not return items at all.
How to send a self addressed stamped envelope step by step
Making a SASE takes a few minutes. These steps cover the usual case of a reply that weighs 1 ounce or less.
- Pick the envelope size. A standard number 10 business envelope works for a letter or a few folded pages. Use a larger envelope only if the reply is bigger than a letter.
- Address it to yourself. Write your name and mailing address in the center, as you would on any letter. Put the return address in the top left corner.
- Add postage. Place one Forever stamp in the top right corner, as shown in where to put a stamp on an envelope.
- Leave it unsealed. The recipient needs to put their reply inside. A sealed SASE cannot hold anything.
- Fold it to fit. Fold the SASE in thirds or in half, so it sits flat inside your outer envelope without creasing the stamp or address.
- Mail the outer envelope. Put the right postage on the outer envelope for its own weight, then send it.
The outer envelope needs its own postage. The stamp on the SASE pays only for the return trip. If you are not sure how much the outer envelope needs, the stamp calculator works it out from the weight.
How many stamps does a SASE need?
Once you know what is a self addressed stamped envelope for, the postage is the next question.
A SASE needs enough postage for the reply and everything in it. One Forever stamp covers a letter up to 1 ounce. The reply the recipient sends back may weigh more than that, especially when they return a manuscript or a bundle of documents.
Letter prices rise with weight. A Forever stamp always equals the current 1 ounce First-Class Mail rate, as explained in what a Forever stamp is. USPS sells Two Ounce and Three Ounce stamps for heavier replies.
| Reply weight | Letter postage (stamped) | Stamp to use |
|---|---|---|
| Up to 1 oz | $0.82 | One Forever stamp |
| Up to 2 oz | $1.11 | Two Ounce stamp, or a Forever stamp plus a 29 cent Additional Ounce stamp |
| Up to 3 oz | $1.40 | Three Ounce stamp |
| Up to 3.5 oz | $1.69 | Forever stamp plus Additional Ounce stamps to reach the total |
These are retail letter prices from the USPS price list, and each extra ounce adds $0.29. For layering stamps, see the price of an additional ounce stamp.
How many stamps you need depends on the final weight, so weigh before you buy.
Example: a manuscript return
Say you want 10 printed pages back. Weigh the full return packet on a kitchen scale to be sure. If it comes in at 1.5 ounces, you need $1.11 in postage, not $0.82.
When in doubt, add the next weight step. Postage that is too low can leave the recipient or you paying the difference. Spending a few extra cents is cheaper than losing a reply.
Size and shape rules that change the price
USPS prices a standard letter by weight only if the piece fits letter limits. A letter can be at most 11.5 inches long, 6.125 inches high and 0.25 inch thick, and the minimum is 5 by 3.5 inches. It may weigh up to 3.5 ounces.
A piece that is square, rigid or bulky can be nonmachinable. That adds a $0.49 surcharge on top of the normal letter price, so keep the contents flat and flexible. USPS also sells a nonmachinable stamp for $1.31, which is the $0.82 letter price plus the $0.49 surcharge.
If the reply is larger than a letter, such as an unfolded manuscript in a 9 by 12 envelope, it becomes a large envelope (flat). A 1 ounce flat costs $1.69 and each extra ounce adds $0.29. A Forever stamp alone will not cover it, so check the price before you mail.
SASE versus business reply mail
A SASE and business reply mail both let the other person respond without paying, but they work differently. A SASE uses regular stamps that you buy and place yourself. Business Reply Mail is a USPS service for businesses that want to be billed only for the replies they receive.
| Feature | SASE | Business Reply Mail |
|---|---|---|
| Who pays | You pay the stamp when you send it | The business pays when the reply arrives |
| Setup | None, just a stamp | Permit and account with USPS |
| Cost for a 1 oz letter | $0.82 stamp | $0.82 plus a per piece fee of $1.31 (basic) or $0.164 (high volume) |
| Annual permit fee | None | $390 |
| Typical user | Individuals | Companies, charities, survey firms |
Business reply envelopes come pre printed, so you do not add a stamp. You may get one with a bill or a donation request. A SASE is the one you make yourself.
Can you send a SASE internationally?
You can send a SASE abroad, but a domestic stamp will not help the recipient overseas. A US stamp pays for mail that starts in the United States. If a person in another country mails your SASE from there, US postage does not cover that trip, and their post office is not required to accept it.
For the outer envelope going out of the country, a 1 ounce international letter costs $1.75 to Canada, Mexico and all other countries. See how many Forever stamps an international letter needs for stamp counts.
International reply coupons used to cover this gap. USPS stopped selling them on January 27, 2013, and the last foreign issued version expired on December 31, 2025, with Post Offices sending the final exchanged coupons in by January 31, 2026. Treat the coupon route as closed and ask the recipient how they prefer to reply.
The practical alternatives are to pay for a reply by another route. You can ask the recipient to scan and email the document, or buy postage from their country’s post office online, or send them the reply cost by a payment app and let them buy local stamps.
Mistakes that cause a SASE to fail
- Sealing it. The reply cannot go in, so the envelope comes back empty or gets ignored.
- Wrong postage. Too little postage can cause delay or postage due on the return trip.
- Reusing stamps. USPS says used stamps cannot be reused, and cutting unused stamps off an old envelope to tape on new mail is prohibited.
- Damaged stamps. Mutilated or defaced stamps are not valid.
- Missing address. Write your own address clearly. A return address on the outer envelope is optional for a stamped letter, as covered in mailing a letter without a return address, but a SASE is useless without your full address on it.
Stamps never expire, so you can prepare SASEs ahead of time. Forever stamps stay valid for 1 ounce First-Class Mail even after prices change. Additional Ounce stamps stay valid for their printed value only.
Bottom line on what a self addressed stamped envelope does
Anyone still asking what is a self addressed stamped envelope can think of it as an envelope you prepare for your own reply. Address it to yourself, add a Forever stamp for up to 1 ounce, and leave it open. Weigh the reply, add more postage if it runs heavier, and keep it flat to avoid the $0.49 surcharge.
