14 USPS Stamp Types (Your Complete Guide)

One of the most prominent hobbies in the world is collecting stamps, otherwise known as philately. While collecting stamps has gained popularity in the past few years, stamps are also critical for mail.

USPS is the best source for pretty much any stamp. But, what are the different types of stamps, and what are they used for? I’ve looked into the matter, and here’s what I discovered!

USPS Stamp Types In 2023

There are several types of stamps, including definitive, commemorative, forever, semipostal, and office mail as of 2023. While you can use some stamps for postage, like forever stamps, others are explicitly collector’s items, like special delivery stamps. Further, other stamps are still available to use as postage, but aren’t as popular anymore.

1. Definitive Stamps

Definitive stamps tend to be what most people think of when they think of stamps.

That said, definitive stamps are produced year after year with no maximum set on the amount produced. Therefore, they are the most common type of stamp since manufacturers make them constantly.

Also, they’re issued in different denominations or price points, which we will discuss later (see numbers 11-14).

Moreover, definitive stamps are issued with a wide range of imagery, including famous people like presidents, different animals, and national landmarks.

2. Commemorative Stamps

Commemorative stamps are the first type of collectible stamp on the list.

With that, commemorative stamps are usually issued to celebrate or commemorate people, anniversaries, events, and things.

Further, commemorative stamps are typically issued as a type of first-class forever stamp. While they can be used as postage, it’s much more common for collectors to buy them.

Additionally, commemorative stamps can be hard to find because they have a limited production run and are issued anywhere from a couple of months up to a year.

Also, another detail that makes these stamps rare is that any unsold commemorative stamps are typically destroyed.

For example, a commemorative stamp would be the stamp issued by USPS in 2012 that celebrated the centennial of New Mexico statehood.

3. Forever Stamps

Forever stamps are a type of stamp that USPS created in 2007.

Forever stamps are the most comparable to definitive stamps. That said, they cost the same and are used for the same purpose; however, forever stamps never lose value.

Because the Post Office is a federally owned and operated institution, the price of postage fluctuates depending on various factors.

For example, one year, definitive stamps could cost $0.45, and the next year cost $0.48, which would render the stamps bought the previous year useless.

But, Forever stamps never lose their value. So, even if you purchase a forever stamp for $0.45 and the postage price increases the next year, you can still use your stamp without buying more stamps.

Also, forever stamps are referred to as permanent stamps, and you can use multiple stamps at a time to ship heavier envelopes.

4. Semipostal Stamps

Semipostal stamps are another popular type of stamp among collectors.

That said, semipostal stamps are issued for special causes or occasions at a higher price, with the price differential going to a supporting organization.

Further, you can use semipostal stamps as normal postage. However, collectors often buy them for their sentimental value.

Moreover, collectors are often attracted to these stamps for the different organizations associated with the causes.

USPS, while providing the semipostal stamp, does not administer any raised funds to these particular causes.

Instead, USPS will coordinate with an outside organization and deliver the funds raised to them for the organization to distribute the funds appropriately.

Also, Congress often compels USPS to issue semipostal stamps to support certain causes by statute.

Additionally, semipostal stamps have been created to help out after natural disasters, raise money for scientific research, or fund organizations providing critical help for people.

If you’re interested in reading about more causes that USPS has issued semipostal stamps for, how much money it raised, and imagery used on semipostal stamps, you can visit this page.

5. Official Mail Stamps

Official Mail stamps have had a complicated history with USPS, and while they’re no longer in circulation, they’re very popular collector’s items.

Official Mail stamps were used mostly for government mail to denote that it was of special import and handled with the utmost privacy.

Since its tenuous history in the United States, Official Mail stamps have become redundant thanks to programs such as Certified Mail, Registered Mail, and the internet enabling many sensitive documents to be encrypted and emailed.

Eventually, USPS officially discontinued Official Mail stamps as postage in 1998.

6. First Day Cover Stamps

First Day Covers, or FDCs, are another type of stamp that can prove to be a valuable collector’s item.

That said, First Day Covers are stamps on an envelope with the date of issuing printed on the envelope to represent that this stamp is part of the very first issue of these stamps.

Typically, these stamps only become valuable if they’re discontinued and postmarked with the date, time, and location of the first release of these stamps.

Further, this is due to the scarcity rules. Otherwise, if the stamp remains in circulation, it is easily accessible to anybody.

If you’d like, you can purchase some First Day Covers on this page of the USPS website.

7. Airmail Stamps

Airmail stamps are another type of postage that has essentially become redundant, except for in certain areas.

With that, Airmail stamps were created in 1918 by USPS for mail explicitly transported by plane.

Back then, it was costly to fly mail by plane, so the consumer who purchased the stamp and USPS shared the cost of shipping.

Now that planes are a far more common shipping method to mail packages, Airmail stamps aren’t necessary for domestic shipments.

That said, Airmail stamps are still issued to help transfer mail from the United States to other countries, although this is not always the case.

8. Postage Due Stamps

Postage Due stamps are the only stamps on this list that don’t have imagery, as it’s only used by USPS employees and for a functional purpose.

That said, Postage Due stamps are stamps used by the Post Office to denote that a piece of mail doesn’t have enough postage on it to cover shipping costs.

Although the sender is the party responsible for ensuring shipping costs are covered, if a piece of mail has a Postage Due stamp, the recipient can be held accountable for the price differential.

Furthermore, Postage Due stamps show different numerals that correspond to the amount that needs to be paid back by the recipient.

The recipient can, of course, refuse to pay the postage, but that means that they’re refusing the letter.

9. Special Delivery Stamps

Special Delivery stamps are another type of stamp that’s no longer used as postage in the United States but is a very popular collector’s item.

With that, Special Delivery stamps first made their debut in the US in 1885 and are largely considered the predecessor to Priority Mail.

Also, you can purchase Special Delivery stamps to help expedite the delivery of a certain mailpiece in the case of an emergency or urgent news.

Moreover, these stamps were used until 1951 and come in various colors corresponding to the stamp’s price.

Additionally, these are arguably one of the most expensive collector’s stamps around as they’re extremely hard to find.

10. Military Stamps

Military stamps are another stamp that has made their way into redundancy with the arrival of the internet.

While still technically in circulation and can be used as postage, they hardly ever are and are typically just collector’s items.

However, military stamps were a type of stamp that allowed letters from military members to be transported efficiently to their destination.

Also, these stamps enjoyed great popularity during World War II and the Vietnam War, helping soldiers stay in touch with their loved ones back home.

Due to the internet, they’re hardly ever used now, thanks to services like instant messaging and video chat services which allow for real-time communication.

11. International Stamps

Denominational stamps are typically separated by their monetary value, nor necessarily their purpose.

That said, international stamps are stamps used for international shipments weighing one ounce per stamp used.

Additionally, you can ship anywhere in the world using international stamps, and they typically cost around $1.30 each and never expire.

12. Nonmachinable Stamps

Nonmachinable stamps are denominational stamps offered by USPS characterized by a butterfly image.

That said, nonmachinable stamps are used for letters or mailpieces that cannot be shipped using today’s typical automated system.

Because the mail can’t be processed the same way most mail is, it’s more expensive to remove it from the process and handle it by hand.

Hence, there’s separate postage to help mitigate the shipping costs. Further, this can be for various reasons, such as:

  • Size of a mailpiece
  • Rigidity of a mailpiece
  • Thickness of a mailpiece and
  • Any buttons
  • Clasps
  • Closure devices

If you need to figure out if you need to purchase nonmachinable stamps for your mail, you can visit this site for more information.

13. Priority Mail Stamps

There are two different Priority shipping services USPS provides: Priority Mail and Priority Mail Express.

With that, both of these shipping services tend to be more expensive due to their expedited nature.

Typically, when people choose to use a Priority shipping service, they use one of the Flat Rate boxes or a pre-labeled envelope.

However, suppose you’re using branded packaging or simply just prefer to use your boxes.

In that case, you can purchase Priority postage, so the local Post Office knows to ship and handle your package accordingly.

Typically, you can only buy these stamps in packs of four, and since they’re for more expensive shipping services, be prepared to spend a good chunk of money.

Further, a pack of four Priority Mail stamps costs just over $30 and delivers within two to three days.

Additionally, a pack of four Priority Mail Express stamps costs over $100 and delivers within one to two days.

14. Additional Ounce Stamps

Additional ounce stamps are the last type of denominational stamp offered by USPS.

That said, this stamp is used when you’re mailing a letter or otherwise small-medium envelope that weighs over one ounce.

Moreover, these stamps are affixed for every ounce over one ounce the letter weighs.

Finally, additional ounce stamps are typically around $0.15 each and sold in rolls of 20 for $4 or 100 for $20.

To know more about USPS, you can also read our posts on whether or not USPS stamps expire, what is certified mail, and if USPS first-class has tracking.


The hobby of collecting stamps is called philately. There are, primarily, 14 different types of stamps offered by the USPS.

However, not all of these stamps are still usable as postage. For example, denominational stamps tend to be characterized by their price rather than by their function.

Also, there are four main types of denominational stamps: international, nonmachinable, priority, and additional ounce.