How Do Stamps Work?


March 23, 2024

In 2022, the United States Postal Service printed an estimated 13.8 billion stamps. The sheer number of stamps in circulation shows how critical these small self-adhesive pieces of paper are to the smooth movement of parcel deliveries in the country. 

But how do stamps work? Are there different types of stamps for different types of mail deliveries?

This article explains how stamps work and how it’s used for mail deliveries. It also tackles the difference between postage and stamps and introduces the Forever stamp. 

Furthermore, this write-up discusses tips on preparing a letter for mailing and the types of stamps one can use. 

If you need the contact information of the post office near you, visit You can access over 31,330 USPS retail offices throughout the country. 

You can head to these facilities to purchase the needed stamps or order them online via the Postal Store or 

Postage Stamps – The Basics

Stamps and postage are standard terms for anyone sending mailpieces via the U.S. Postal Service. However, many may need clarification on whether these terms have different meanings. Stamps are small adhesive pieces of paper with a specific value issued by USPS. 

On the other hand, postage is the amount you must pay USPS to deliver your mail or package. You can buy these postage stamps as booklets, sheets, or coils. 

Many stamps are available for purchase, but one is somewhat special. This special stamp provided by the Postal Service is the Forever stamp. 

What Are Forever Stamps?

One special USPS postage stamp is the Forever stamp, which can be used to pay for postage for a one-ounce letter sent via First-Class Mail. 

What’s special about this stamp is that once you’ve bought one, you can always use it anytime to send one-ounce letters, even if postage prices have increased in the future. 

The Forever Stamp Program’s Success Is a Win for Everyone

Forever stamps offer a solution to the problem of disposing of obsolete stamps when price rates increase. Businesses don’t have to buy additional stamps after prepurchasing several of them before a postal rate increase. 

You can stock on Forever stamps and won’t have to work about price rate increases for First-Class Mail. A Forever stamp’s value is always the current rate for sending a 1-oz letter via First-Class Mail.

Why Are Forever Stamps Great for Entering Sweepstakes?

Forever stamps can be great when you regularly enter the sweepstakes via mail. 

You don’t have to worry about increasing stamp prices, which may become costly if you send more than one sweepstakes entry. 

So, using Forever stamps is economical when sending First-Class Mail via USPS regularly. 

Why Is Forever Crossed Out on Forever Stamps?

USPS only crosses out the word “forever” in a Forever stamp on the online images to prevent counterfeiting. 

Technology is constantly upgrading, and many counterfeiters have the means to create relatively believable copies of a particular stamp. 

So, don’t fret if all of the Forever stamps you browse at have crossed out the “forever” word. It’s an anti-counterfeiting strategy used by the Postal Service. 

Note that the “forever” word is not crossed out once you receive the physical Forever stamp. 

What Are the Benefits of Forever Stamps?

Forever stamps can benefit you in three ways. First is that they help you save money. Instead of buying different stamps and adding stamps when postage rates increase, you only need one Forever stamp to send a 1-oz letter. 

The second benefit is convenience. You won’t need to combine stamps just to send First-Class Mail. You only need one Forever stamp every time. 

Finally, Forever stamps help save time. Once you purchase a Forever stamp, you can use it anytime. You don’t have to consider whether the price rates have increased. If you’re paying First-Class postage, one Forever stamp is all you need. 

How Do U.S. Stamp Rates Work?

USPS doesn’t arbitrarily set the stamp rates. The Postal Service is prohibited from setting the stamp prices at any value they desire. 

The Postal Regulatory Commission, an agency overseen by the U.S. Congress, determines the rate. The price increase is typically based on inflation and rising expenses running a complex business like the Postal Service. 

How Do Forever Stamps Work?

Forever stamps work because the Postal Service regards that the value of this stamp is always the current value of First-Class Mail. With that in mind, it’s easier to understand how this type of stamp works. You have a stamp that doesn’t lose or diminish in value. 

Tip: Forever Stamps Don’t Last Forever

The Forever stamp’s value is forever, but the physical stamp isn’t indestructible. If you don’t take care of your physical Forever stamps, they can get damaged beyond recognition. 

Once your Forever stamps get torn, damaged, or unreadable, they will lose their value because the Postal Service can’t determine the value of the postage stamp.

Where to Buy the Stamps You Need and the Postage Costs

You can buy stamps, including Forever stamps, in more than one place. You can buy it at your local post office. You can also shop online through the Postal Store,, and other third-party sites. 


You must pay the following postage prices if you send letters or parcels that fit this category via USPS. A mailpiece is considered a letter if the weight and dimensions are the following:

  • Letter length: minimum of 5in, maximum of 11 1/2in
  • Letter height: minimum of 3 1/2in, maximum of 6 1/8in

Domestic Letter Mailing – Price per Ounce

The domestic price for a 1-oz letter sent via First-Class Mail is $0.66. An additional ounce for letters and large envelopes is $0.24. You can use First-Class stamps for postage or a Forever stamp if you’re mailing 1-oz letters. 

International Shipping Letter Postage

The cost of a First-Class Mail International letter starts at $1.50. This price is also the same as a Global Forever stamp for mailpieces sent abroad. So, instead of combining more than one stamp, you can use Global Forever stamps for postage. 

Flat Rate Envelopes

Shipped via Priority Mail service, a USPS flat-rate envelope is packaging with a set price. Instead of basing the postage on the weight and dimensions of the packages, a flat-rate envelope has a fixed rate as long as your parcel doesn’t exceed 70lbs in weight. 

Domestic Envelope Requirements and Costs

The flat-rate domestic envelope has the following dimensions and costs. You can refer to this list to plan your shipping expenses. 

Priority Mail ExpressDimensionPrice
Flat-rate envelope12-1/2in x 9 1/2in$28.75
Legal flat-rate envelope15in x 9 1/2in$28.95
Padded flat-rate envelope12-1/2in x 9 1/2in$29.45
Priority MailDimension Price
Flat-rate envelope12 1/2in x 9 1/2in or smaller$9.65
Legal flat-rate envelope15in x 9 1/2in$9.95
Padded flat-rate envelope12 1/2in x 9 1/2in$10.40

Domestic Postcard Shipping

A postcard is a mail sent without an envelope. It’s usually made from a card, where the message is written directly at the back. The current price for standard-sized, rectangular postcards starts at $0.51 

International Mail and Packages

Here are some USPS mail services for international deliveries. 

Priority Mail Express InternationalDimensionPrices
Flat-rate envelope(max weight: 4lbs)
12 1/2in x 9 1/2in and 15in x 9 1/2in
$54.75 to $75.55
Priority Mail InternationalDimensionPrices
Flat-rate envelopes(max weight: 4lbs)
12 1/2in x 9 1/2in and 15in x 9 1/2in
$30.35 to $44.70
Small flat-rate box(max weight: 4lbs)
8 5/8in x 5 3/8in x 1 5/8in inside
8 11/16in x 5 7/16in x 1 3/4in outside
$31.45 to $46.40
Medium flat-rate boxes(max weight: 20lbs)
11in x 8 1/2in x 5 1/2in inside
11 1/4in x 8 3/4in x 6in outside
13 5/8in x 11 7/8in x 3 3/8in inside
14in x 12in x 3 1/2in outside
$60.55 to $102.55
Large flat-rate boxes(max weight: 20lbs)
11 3/4in x 12in x 5 1/2in inside
12in x 12 1/4in x 6in outside
23 11/16in x 11 3/4in x 3in inside
24 1/16in x 11 7/8in x 3 1/8in outside
$74 to $132.05

What Forever Stamps Are Worth?

A Forever stamp is First-Class Mail domestic’s price, currently $0.66. On the other hand, the Global Forever stamp is the same price as First-Class Mail International, currently at $1.50. 

How to Save Money On Forever Stamps

You can hunt for bargains in online shops like or the Postal Store. You can also check out sales on eBay and other retail stores. However, you have to watch out for counterfeits. You can also purchase Forever stamps using credit cards and using promos.  

A Better Way to Manage Shipping Costs

Sometimes, you don’t need any special managing software or process to manage shipping costs. All you need is to be thorough in your preparation. 

For instance, ensuring you place the correct address and the right stamps (postcard stamps for postcards) when you mail letters or postcards will prevent delays. 

You can also use the stamp cost guide to ensure you use the right number of cent stamps and other higher-denomination stamps when paying postage. 

Finally, using standard-size envelopes is much more practical than over-sized envelopes or postcards. If it doesn’t need to be that big, why ship it?

How Do You Know How Many Stamps to Use?

Stamps have different denominations, and you combine each of these denominations to match the postage price of the mailpiece you want to ship. The number of stamps you use depends on the stamp type and the postage. 

Calculating Postage at the Post Office

You can take your parcel to the post office and ask the window clerk the number of stamps you need to buy. 

Using a Postage Calculator

You can access this type of calculator online. USPS provides a postage calculator that you can use to check how much postage you need to pay for a particular package. 

How Many Stamps Do You Need to Send a Letter?

It depends on the weight of the letter and its destination. If the letter weighs 1oz, you can use one Forever stamp to pay for the first ounce. Likewise, you can use one Global Forever stamp if the mailpiece is bound for international addresses. 

How Many Stamps Do You Need for Canada?

You only need one Global Forever stamp to send a standard mail to Canada. If you send heavier packages, you must add stamps for every ounce. 

Do You Need to Use Two Forever Stamps?

One Forever stamp is usually enough to send regular mail domestically. You don’t need to use two Forever stamps unless the postage price is equal to two Forever stamps.

What Happens if You Don’t Have the Right Amount of Stamps?

If your package doesn’t have the right amount of stamps, it will be returned. This delay can cause inconveniences, especially if you’re running an eCommerce store. 

How Do You Check if a Stamp Is Real?

Counterfeit and forgeries are problems in stamp collecting and regular mailing activities. 

  • Check if the stamp is re-gummed. Self-adhesive stamps use “gum” to stick to the envelope. Some counterfeiters “re-gum” a stamp to make it look new. 
  • Check any perforations, crumpled edges, and other telltale signs that it’s not an authentic stamp. 

You may not be able to stop a fake stamp immediately. However, you can always seek the help of an expert stamp checker or your local post office to ensure you don’t get scammed. 

Send Mail: Step-by-Step Instructions

Here is a simple step-by-step guide on how to send mail via USPS. Remember that it’s best to understand this fully to avoid mailing problems in the future. 

Choose an Envelope or Postcard

Choose what’s appropriate and works well with the recipient and your message. If a letter inside an envelope is the most appropriate way to send your message, use it. However, if you feel that a postcard will give your correspondence more style and personality, use it. 

Address Your Mail

Properly writing your address is crucial for deliveries. If you write the wrong address, it will result in delays, confusion, and missed deliveries. Your package may be delivered to the wrong house or get stuck in the post office because of an incorrect address. 

Address Format Tips

When formatting your address, use the following tips:

  • Write the address in capital letters. Ensure that you write it neatly.
  • Use a pen or any permanent marker when writing the address.
  • Don’t use commas or periods.
  • Always include the ZIP (Zone Improvement Plan)+4 code if possible.

Write the Sender‘s Address

Your address is also the return address. Write this at the top-left corner of the envelope and do the following lines:

  • Full name or company name
  • Apartment or suite number
  • Stress address
  • City, state, and ZIP+4 code

Write Delivery Address

The delivery address is also the recipient’s. You write the delivery address at the center of the envelope. You can follow the formatting instructions. 

  • Recipient’s full name or company name
  • Apartment number or suite number
  • Full street address
  • City, state, and ZIP+4 code

Special U.S. Addresses

The United States designates areas as “special” U.S. addresses. The following are tips anyone can use when sending mail to these locations. 

Puerto Rico

For addresses in Puerto Rico, you must add an urbanization or community code to specify the area or development. You can notice this from the abbreviation “URB” in an address.

SAN JUAN PR 00926-3232

U.S. Virgin Islands

These islands are abbreviated “V.I.” and use the same standard address style as another domestic address format. 

Military and Diplomatic Mail (APO, FPO, or DPO)

When writing to any military or diplomatic installations, you can do the following:

  • Don’t include the city or country where the installation is located
  • Include the unit and box numbers if they’re assigned

Note that the Army or Air Force Post Office (APO), Fleet Post Office (FPO), and Diplomatic Post Office (DPO) are considered domestic locations according to USPS. 

Additional Postage

Any additional ounces mean additional postage. So, even if one has used a Forever stamp for mail, if the weight and postage exceed the recommended weight for First-Class Mail, one may need to pay additional postage. The price for an additional ounce for letters and large envelopes is $0.24.

Add-On Services

You can include additional services for mail services that you’ve purchased. Examples of these add-on services are the following:

  • Adult Signature: An add-on requiring the signature of an adult person (21 years and above).
  • Certificate of Mailing: Provides proof of mailing.
  • Certified Mail: Provides proof of delivery and proof of mailing.
  • Insured Mail: provides insurance against loss or damage of up to $5,000.
  • Registered Mail: A mailing service with maximum security and proof of mailing. 
  • USPS Tracking: A service used to monitor package status during deliveries. This service is automatic for most USPS mailing services.

Send Your Mail

Once you’ve completed everything— placed the appropriate stamp, and written the correct address and the right add-ons— you can ship your mailpiece. You can pick up your packages at your home or drop them off at your nearest local post office. 

If you need the contact information of the post office near you, visit You can access over 31,330 USPS retail offices throughout the country. 

History of Stamps

Before the appearance of paper stamps, letters were hand-stamped or postmarked with ink. The English Postmaster Henry Bishop invented this “stamping” method, first called the “Bishop mark.” The London General Post Office first used this postmark in 1661. 

The first postage stamp started with Great Britain’s Penny Post and the British Penny Black Stamp released in 1840. The “Penny Black” has an engraving of Queen Victoria’s head in profile. This engraving remained on all British stamps for the next 60 years. 

The first adhesive stamp was invented in 1837 by Sir Rowland Hill, an English schoolmaster. This new stamp was so innovative that he was knighted for it. 

From there, the modern stamp developed, and it has now become a staple commodity for anyone using the Postal Service to send mail.

History of Forever Stamps

The first Forever stamp was sold in April 2007, featuring the Liberty Bell, an icon of American independence. In 2011, all First-Class Mail 1-oz stamps became Forever stamps, with the exceptions of 500, 3,000, and 10,000 stamps in coils.


  1. Postal Facts
  2. Postage Stamps – The Basics
  3. Forever Stamp Fact Sheet
  4. What Are You Mailing? Domestic*MTY5ODAxMDcxOC4xNzMuMS4xNjk4MDExNTI5LjAuMC4w
  5. First-Class Mail International
  6. Price List
  7. Mailing & Shipping Prices
  8. First-Class Mail
  9. Send Mail: Step-by-Step Instructions