You can mail a package using postage stamps, and USPS accepts them as payment across its main shipping services. The catch is the 10-ounce rule: any stamped package over 10 ounces or thicker than half an inch has to be handed to a clerk at a Post Office counter, and stamped packages don’t come with the free tracking a printed label would give you. For a small, light parcel you already have enough stamps for, it works fine. For anything heavier, expect a counter visit and a lot of stamps on the box.
Which Shipping Services Take Stamps
Stamps are accepted as payment for the three main domestic package services:
- USPS Ground Advantage, the standard affordable option, for packages up to 70 pounds.
- Priority Mail, typically one to three business days, up to 70 pounds.
- Priority Mail Express, overnight to two-day delivery, up to 70 pounds.
The 70-pound cap applies across all three. Anything heavier is nonmailable through USPS.1USPS. Parcel Size, Weight and Fee Standards
Size matters too. Combined length and girth can’t exceed 108 inches for Priority Mail or Priority Mail Express, or 130 inches for USPS Ground Advantage. Length is the longest side; girth is the distance around the thickest point (2 × width + 2 × height).1USPS. Parcel Size, Weight and Fee Standards
How Much Postage and How Many Stamps
Postage depends on weight, dimensions, destination zone, and service. The reliable way to get an exact number is the USPS Price Calculator at usps.com. Enter the package details and it returns the required postage.2USPS. First-Class Mail and Postage
Once you have the total, divide by $0.78 (the current Forever stamp value) and round up. You can overpay postage; you can’t underpay. A package that costs $9.36 in postage needs exactly 12 Forever stamps. One that costs $9.50 needs 13, because 12 stamps only cover $9.36. There is no refund on overpayment, so every stamped package effectively rounds up to the next $0.78 increment.3USPS. January 2026 Price Change – FAQ
Forever stamps are worth the current First-Class letter rate regardless of when they were bought, so older Forever stamps you paid $0.55 or $0.63 for still count for $0.78 today.2USPS. First-Class Mail and Postage Semi-postal fundraising stamps like Breast Cancer Research and Save Vanishing Species cost $0.85 each, and the full face value counts toward postage.4About.usps.com. Semipostal Stamps Older denomination stamps still work at their printed value. You can mix any of these on the same package as long as the total meets or exceeds the required postage.
Underpaying is not a small mistake. USPS returns underpaid mail to the sender without attempting delivery. If there is no return address, it becomes dead mail and may never reach anyone. Weigh the package on a reliable scale and use the online calculator instead of guessing.
The 10-Ounce Rule
This is the rule that changes everything about mailing stamped packages. Under USPS security regulations sometimes called the Anonymous Mail rule, any stamped mailpiece that weighs more than 10 ounces or measures more than half an inch thick must be handed directly to a postal employee at a Post Office counter. You cannot drop it in a blue collection box, a lobby drop, an apartment mailbox, or any other unattended location.5Federal Register. Stamped Mail
The rule exists because stamps are anonymous. There is no electronic record linking the sender to the package the way there is with online postage or metered mail. It applies regardless of service, covering Ground Advantage, Priority Mail, Priority Mail Express, and Media Mail.5Federal Register. Stamped Mail
Drop a stamped package over 10 ounces into a collection box and USPS returns it to the sender. No return address means it becomes undeliverable. Most packages weigh more than 10 ounces, so most stamped packages need a trip to the Post Office.6USPS. What is a Collection Box
Where to Drop It Off
Blue collection boxes only work for stamped items 10 ounces or lighter and half an inch thick or thinner. Adding USPS Tracking or Signature Confirmation doesn’t change those limits.6USPS. What is a Collection Box
For everything else, you’re going to the Post Office counter. That includes any stamped package over 10 ounces or thicker than half an inch, any international shipment that needs a customs form, and anything you want to add extra services to.6USPS. What is a Collection Box
USPS offers free Package Pickup from your home for some shipments, but stamped packages face the same 10-ounce and half-inch limits. If it’s over, it has to be presented in person, which effectively rules out Package Pickup for most stamped parcels.7USPS. Package Pickup and Pickup on Demand
Tracking and Insurance
Priority Mail and Priority Mail Express both include free tracking and built-in insurance, but only when the package carries a USPS Tracking barcode. Buying postage online or at the counter gives you a label with that barcode. Paying with stamps alone does not, which means no tracking and no way to claim the included insurance.8USPS. Insurance and Extra Services
The workaround: bring the stamped package to the counter and ask the clerk to add a tracking label. Extra service fees, including insurance, can be paid with stamps in most cases. Registered Mail and a few specialty services have their own payment requirements and are the exceptions.9Postal Explorer. 503 Extra Services Since any stamped package over 10 ounces already requires a counter visit, asking for tracking at the same time costs you nothing extra. For anything valuable, ask.
Preparing the Package
Use a sturdy box that fits the contents with room for bubble wrap or packing peanuts. Items should be snug enough not to shift when the box is shaken. Reinforce the bottom with at least one extra strip of packing tape.10USPS. What is the Best Way to Prepare a Parcel for Shipping
Seal all seams with clear or brown packing tape at least two inches wide. Reinforced packing tape and paper tape also work. Do not use string, twine, cord, masking tape, or cellophane tape. String and twine catch on sorting equipment, and masking tape doesn’t hold up to processing.11Postal Explorer. Preparing Packages
Addressing and Stamp Placement
Write the recipient’s full name and address, including ZIP+4 if you have it, in the center of the package in clear block letters. Put your return address in the upper-left corner. A legible return address is especially important on a stamped package, because if anything goes wrong with the postage, that address is the only way the package comes back to you instead of disappearing into the Mail Recovery Center.
Affix stamps in the upper-right corner. Keep them flat, secure, and non-overlapping so automated sorting equipment can read them. On a package that needs 15 or 20 stamps, that takes real estate. Arrange them in neat rows and make sure none peel up at the edges. A strip of clear tape over the stamps isn’t a bad idea for packages that will see rough handling.
International Packages
Stamps can cover the postage on an international package, but they don’t replace the customs documentation international shipments require. If you’ve prepaid postage with stamps and the package needs a customs form, visit your Post Office, fill out form PS 2976-R, and present the package to a clerk who will create the customs label.12USPS. Customs Forms
You can also complete the customs form online through USPS Customs Form Online or Click-N-Ship before heading to the Post Office. That saves time at the counter, but international stamped packages still have to be presented to an employee in person.7USPS. Package Pickup and Pickup on Demand
When Stamps Are Worth It
Stamps work best for lightweight domestic packages when you already have enough stamps on hand and don’t mind visiting the Post Office anyway. For a small item under 10 ounces, stamps let you skip the counter entirely and use a collection box.
They get impractical fast for heavier packages. A Priority Mail Flat Rate Envelope costs $11.95 at the counter, which needs at least 16 Forever stamps to cover. A larger Priority Mail or Ground Advantage shipment might need 30 or 40 stamps, which is a physical challenge just to fit on the box. You also skip the discount of online postage, which offers commercial rates below retail, and without a printed label you lose automatic tracking unless you ask a clerk to add it.13USPS. Postage Rates and Prices
The sweet spot is a small, light parcel and a book of stamps already in your desk drawer. For anything heavier or more valuable, buying postage online gives you tracking, a lower price, and a cleaner-looking package.