First-Class Mail Stamp


March 12, 2024

First-Class Mail is among the popular services the United States Postal Service (USPS) offers, with 48.9 billion in volume delivered in 2022.

With this figure, there should be enough First-Class Mail pieces to go around and keep USPS busy. Aside from delivering First-Class Mail, the Postal Service has the task of selling postage in the form of stamps.

How do you purchase stamps required for First-Class Mail? How much do these stamps cost? Can you use regular stamps for First-Class Mail?

This article answers these issues and discusses what you need to know about First-Class Mail. This article also explores the different First-Class Mail types and when you should expect your mail to arrive.

Visit and use its online search tool to find a post office near you and start sending First-Class Mail. is also an excellent resource for your mailing and shipping needs to help you become an informed shipper or recipient.

How to Buy Stamps for First-Class Mail Postage

When purchasing First-Class Mail stamps, you can choose between regular and Forever stamps. You can use Forever stamps to mail one-ounce letters regardless of when you buy the stamps.

Forever Stamps are available at post offices nationwide, online at, and by phone at 1-800-STAMP-24 (1-800-782-6724). USPS sells these stamps in booklets and sheets of 20.

How Heavy Can a Letter Be for a First-Class Stamp?

When sending a letter using the USPS First-Class Mail service, consider its weight, as this factor can affect your postage costs. The following section discusses the weight considerations for sending First-Class Mail.

The Maximum for How Heavy a First-Class Letter Can Be Is 3.5 Ounces

A First-Class Mail letter’s maximum weight should not exceed 3.5 ounces (oz). If you want to mail a heavier letter, consider sending it as a First-Class Mail envelope, weighing up to 13oz.

Cost of First-Class Stamps

The cost to send First-Class Mail depends on whether you want to mail a letter or postcard or are shipping domestically or internationally. These costs are discussed in the following sections.

Letter Stamps

As of July 2023, stamped letters have the following First-Class postage costs:

Weight not exceeding (oz)Price

Postcard Stamps

If you want to send a standard-sized postcard, prices start at $0.51. Meanwhile, oversized postcards require letter stamps, which start at $0.66.

Global Forever (International)

When sending letters internationally, you can use the First-Class Mail International service. For example, to send a 1-oz letter anywhere worldwide, use one Global Forever stamp, which costs $1.50 and does not expire, even if the postage increases.

“Can I Use Regular Stamps for First-Class Mail?”

When sending a First-Class Mail letter heavier than 1oz, you can use one Forever stamp and regular additional postage stamps to ensure delivery.

The Postal Store sells additional postage stamps with different denominations, such as $0.01, $0.02, $0.03, $0.04, $0.05, and $0.10.

What’s the Difference Between First-Class and Regular Stamps?

One difference between a First-Class Mail Forever stamp and regular ones is that you only need one Forever stamp to send a 1oz letter costing $0.66.

Meanwhile, purchasing regular stamps with smaller denominations means buying several such stamps until you reach $0.66 for a 1oz mail.

First-Class: Everything You Need to Know

One of the most popular USPS services for shipping domestic mail is First-Class Mail. If you want to send a letter or document weighing 3.5oz or less, consider sending it through this service.

Prices start from $0.51 for postcards and $0.66 for letters. These costs make First-Class Mail among the most affordable USPS services for these types of mail.

However, this service does not have tracking and insurance. You have to purchase different add-ons as an alternative for these features.

What Is First-Class Mail?

First-Class Mail is available at your local post office or through an approved third-party courier. Although letters, large envelopes (flats), and postcards are not eligible for USPS Tracking, optional services like Collect on Delivery (COD) and Return Receipt provide some tracking information.

What Makes First-Class Mail a First-Class Service?

The U.S. Postal Service treats First-Class Mail as a higher priority class service than Retail Ground (incorporated into USPS Ground Advantage service), Marketing Mail, or Media Mail. In other words, First-Class Mail’s delivery speed should come first over those services.

How Does First-Class Mail Work?

First-Class Mail is an easy and affordable service for sending and delivering envelopes and postcards in one to five business days. The cost to send First-Class Mail depends on the item’s weight and shape.

Is First-Class Mail the Same As Regular Mail?

Although First-Class Mail is one of many USPS services, it is basic. In other words, all mail items you send are first-class or regular. Furthermore, all letters, postcards, legal documents, forms, and other correspondence businesses regularly send out are also regular mail.

USPS First-Class vs. Priority Mail

First-Class Mail is an excellent choice for sending non-urgent letters and envelopes since they arrive in one to five business days, as mentioned earlier.

On the other hand, Priority Mail works well for crucial items that must arrive in one to three business days.

While First-Class Mail lets you send letters not exceeding 3.5oz or flats up to 13oz, Priority Mail allows envelopes and packages up to 70 pounds (lbs).

Another significant difference is that First-Class Mail does not include insurance and tracking upon purchase. In contrast, Priority Mail has tracking and up to $100 insurance.

What Is Presorted First-Class Mail?

You can presort your mail (sorting and bundling mail by service type, size, and ZIP code) if you want to ship 500 or more items. Presorted mail is eligible for a 20% reduced shipping rate, so presorting can help you reduce shipping costs. The standard delivery time for presorted mail is similar to regular First-Class Mail.

“Can I Upgrade First-Class Mail?”

When using First-Class Mail, you can upgrade it to Certified Mail or Registered Mail, which offers add-ons like the following:

  • Return Receipt
  • Insurance
  • Collect on Delivery (COD)
  • Proof of mailing
  • Signature Confirmation
  • Special handling

What Are the Different Types of First-Class Mail?

First-Class Mail consists of several services that cover domestic and international shipping. The following sections discuss these First-Class Mail types.

First-Class Mail

This domestic service offers the best prices for items up to 13oz and is eligible for Delivery Confirmation services like Certified Mail. If you are the shipper, Certified Mail provides a mailing receipt confirming that your item has been sent.

First-Class Mail International

First-Class Mail International (FCMI) is USPS’ most affordable service for sending letters and large envelopes to more than 180 countries.

Using this service, you can send 1-oz postcards or letters worldwide with one Global Forever stamp. This stamp costs $1.50 as of 2023 and does not expire.

If you want to send flats up to 15.994oz, postage prices can vary depending on destination and weight.

First-Class Package Service

As of 2023, USPS no longer offers this service and renamed and incorporated it into USPS Ground Advantage. This new service lets you send items under the following weight ranges:

  • Up to 4oz
  • Up to 8oz
  • Up to 12oz
  • Up to 15.999oz
  • Up to 70lbs in 1-lb increments

Delivery is in two to five business days and includes tracking, free package pickup, and a $100 insurance coverage.

What Is the Postage for First-Class Mail?

As mentioned earlier, postage for First-Class Mail starts at the following prices:

  • Letters: $0.66
  • Postcards: $0.51
  • Flats: $1.35
  • Oversized, square, or unusually shaped envelopes: $1.06
  • Oversized postcards: $0.66

Summary of Features for First-Class Mail

USPS First-Class Mail’s features, as discussed in this article, are summarized as follows:

  • Delivers mail in one to five business days
  • Offers best prices for items up to 13oz
  • Qualifies for Delivery Confirmation services like Certified Mail
  • Implements one price for commercially priced cards and letters up to 3.5oz
  • Offers prices according to weight and shape

“How Can I Pay for USPS First-Class Mail Postage?”

If you are a small business owner, USPS offers several payment options for your First-Class Mail postage.

One such method is through your account. You can use this account to pay for postage and print one or several shipping labels online.

How to Send First-Class Mail

To send an item through First-Class Mail, prepare your mail and place it inside an envelope. Next, address your envelope and affix a First-Class stamp on it. Afterward, drop the envelope in a nearby collection box or post office.

How to Track First-Class Mail

As mentioned, USPS First-Class Mail does not have tracking options. When sending letters, flats, and postcards through First-Class Mail, you are ineligible to receive a tracking number from USPS.

One exception is First-Class Package Service, renamed as USPS Ground Advantage. This service includes tracking. To track, go to the USPS website and enter your item’s tracking number into the search box.

How Long Does First-Class Mail Take to Deliver?

If you are the shipper, your recipient should get the mail within an estimated time, depending on the service you use. The following sections discuss First-Class Mail’s published delivery times and factors that can affect arrival schedules.

Mail in 1 to 5 Business Days; Small Packages in 2 to 5 Business Days

When you use First-Class Mail to send letters and postcards, they should arrive within one to five business days. If you want to send packages through Ground Advantage (formerly First-Class Package Service), arrival should be in two to five business days.

Meanwhile, mail sent internationally through First-Class Mail International or First-Class Package International Service will have varying delivery times depending on the destination.

Severe Weather Conditions

Adverse weather or natural emergencies can cause difficulty moving from one place to another. Under such circumstances, postal workers may end up pausing their duties, causing deliveries to stop or get delayed until the weather eases.

Incorrect and Invalid Addresses

Invalid or wrong addresses, such as one incorrect digit in the ZIP code, can cause delivery delays. So, the time it takes for USPS First-Class Mail to arrive can depend on how correctly you write the address.

Double-check the details when writing the mailing address on your postcards, parcels, or letters. Write using legible handwriting so that postal workers can understand the address.

Federal Holidays

These holidays are when USPS offices are closed. Therefore, you should expect the Postal Service not to deliver mail during these days.

Still, some offices may be open during these holidays and allow delivery. Contact your local post office to ask whether it is available on such days.

Backlog at the Sorting Facility or Post Office

Post offices generally experience a massive mail surge from Thanksgiving until New Year’s Day. Businesses will likely send numerous marketing letters and postcards to customers and prospects during this period, and online shopping activity will rise.

These factors can cause a backlog in the post office. Usually, postal workers struggle to meet this sharp demand, so expect delays during these situations.

Additional First-Class Mail Services

One optional service you can add to your First-Class Mail is Certified Mail. It provides a delivery confirmation and receipt of mailing, which can function as evidence, especially during legal disputes.

Another service to consider using as an add-on for First-Class Mail is Registered Mail. It offers additional protection for your mail items and provides proof of mailing and delivery.

Weight, Size, and Shape Requirements

As mentioned, First-Class Mail letters must weigh 3.5oz or less to qualify for standard pricing. If your item is oversized or irregularly shaped, it may incur additional charges. The following sections tackle these charges.

Additional Charges for Irregular Mailpieces, Envelopes, and Small Packages

Some mail items that do not adhere to USPS size and weight standards for First-Class Mail can incur additional charges. These nonstandard items are discussed in the following sections.

Nonmachinable Envelopes

Unusually shaped mail, such as vertical or square envelopes and mail with buttons or clasps, are charged a nonmachinable surcharge, even if these parcels weigh less than 1oz. The sections below discuss nonmachinable First-Class Mail items.

First-Class Mail Postcards

Oversized postcards require letter stamps, meaning the item is charged with letter rates starting at $0.66. This cost is a 15-cent increase from the $0.51 postage ($0.66-$0.51=$0.15) when mailing standard-sized postcards.

First-Class Mail Letters

For oversized, square, or unusually shaped envelopes, USPS charges begin at $1.06. Standard First-Class Mail postage starts at $0.66, meaning stamps for nonstandard letters cost an additional $0.40 ($1.06-$0.66=$0.40).

Large Mailpieces, Envelopes, and Small Packages

Letters exceeding the maximum envelope length, height, or thickness for First-Class Mail are charged large envelope prices. Prices start at $1.35.

First-Class Mail Flats

These flats are non-rectangular, rigid, exceeding maximum dimensions, or not uniformly thick large envelopes. USPS charges these parcels with package prices and ships them with USPS Ground Advantage.

First-Class Package Service Parcels

Packages sent via USPS Ground Advantage (formerly First-Class Package Service) have a starting shipping price of $4.75. However, you can sign up for an online Click-N-Ship service (an application that helps you store and manage your labels) for lower commercial mail rates.

Features and Pricing

Aside from weight, size also affects pricing. The sections below list the minimum and maximum size dimensions for First-Class Mail.


For USPS to charge your First-Class Mail letter with standard postal rates, the item must adhere to the following minimum and maximum dimensions:

Minimum5 inches (in)3.5in


If you want to send postcards, USPS requires their dimensions to follow these sizes:


Large Envelopes or Small Packages

To mail large envelopes, follow the dimensions in the table below:


If you want to send a package, the maximum length plus girth should measure 108in. If you wish to use Ground Advantage, the maximum should be 130in.

Additional Information

Aside from weight and size requirements, other information you need to know when sending First-Class Mail includes restrictions on prohibited items and business discounts. This additional information is explored in the following sections.

Mailing Restrictions and Prohibitions

When mailing prohibited, restricted, or hazardous materials through First-Class Mail, you must comply with specific standards and regulations. For example, items that cannot be shipped domestically include the following:

  • Gasoline
  • Ammunition
  • Marijuana (medical or otherwise)
  • Air Bags
  • Explosives
  • Liquid mercury

For Businesses

If you are a business that frequently sends mail, some elements you may look for are speed, security, affordability, and customer service. The following USPS business solutions can help you provide these services and resources to your clients at discounted rates.

Data-Driven Shipping

First-Class Mail offers services like forwarding and address correction that may benefit your business. You can offer these services to help you reach a broader target audience.

Commercial Prices and Automation Discounts

Your First-Class Mail item can qualify for commercial pricing if you mail presorted letters or flats numbering at least 500 mailpieces. Bulk discounts due to automation can also apply.

Where to Buy Stamps Online

USPS has an online store where you can purchase as many stamps as you want. Other online retailers like also sell stamps and even let you print postage from home. 

You can also purchase stamps by calling 1-800-STAMP-24 (1‑800‑78267-24) or visiting your local post office, grocery store, pharmacy, or gas station.

“How Many Stamps Must I Put on an Envelope?”

The number of stamps you place on the envelope depends on the postage the post office determines. This postage is usually based on the item’s size and weight.

Suppose you want to send a postcard whose postage is $0.51. The number of stamps you buy should equal that amount, such as five stamps worth $0.10 and one stamp worth $0.01 [($0.10 x 5) + $0.01 = $0.51].

“How Many Forever Stamps Do I Need?”

One Forever stamp costs $0.66, meaning you can use one such stamp to send a 1-oz First-Class Mail item. However, depending on how heavy your mail is, you may need to purchase a combination of Forever and additional-ounce stamps.

“How Many Stamps Do I Need to Mail a Letter?”

Suppose you want to send a 2-oz letter. Consider purchasing one Forever stamp for the first ounce and additional-ounce stamps for the extra weight instead of buying two Forever stamps.

One reason is because two Forever stamps cost $1.32 ($0.66 x 2 = $1.32). Meanwhile, postage for a 2-oz letter is only $0.90. In other words, two Forever stamps cost more than the letter’s postage price.

How Many Stamps Are There in a Book?

A standard USPS stamp book for First-Class Mail contains 20 stamps you can apply to envelopes and on First-Class postage.

The Postal Store sells Forever stamp books that cost $13.20 ($0.66 x 20 = $13.20) and come with multiple designs.


Price can be essential when deciding what service to send your mail or package. The following sections provide a closer look at these prices.

Domestic Prices

To send a parcel within the U.S. using First-Class Mail, refer to the following services and their starting prices as of 2023:

  • First-Class Mail: Prices start from $0.66 at the post office and $0.498 with commercial pricing.
  • USPS Ground Advantage (formerly First-Class Package Service): Prices start from $4.75 at the post office and $3.59 with commercial pricing.

International Prices

For sending mail from the U.S. to another country or region, the following starting prices apply for international First-Class services:

  • First-Class Mail International: Prices start from $1.50 for letters and postcards and $3 for flats for all countries.
  • First-Class Package International Service: Prices start from $15.75 at the post office, $14.96 with Commercial Base, and $14.96 with Commercial Plus.

Holiday Shipping Rate Increase Info

For the 2023 peak holiday season, USPS announced it will not implement any additional surcharges.

In 2022, USPS levied a temporary shipping rate hike for peak holidays from October 2, 2022, until January 22, 2023. This rate increase affected several USPS services, including First-Class Package Service (not yet renamed to USPS Ground Advantage at the time).

Info on the 2023 USPS Postage Rate Increase (Implemented July 9, 2023)

On July 9, 2023, USPS implemented a postage price increase that raised the Forever stamp’s price by three cents from $0.63 to $0.66. This increase represents an estimated 5.4% increase in First-Class Mail prices to help offset inflation.

Other types like metered mail, domestic postcards, and international letters also increased. However, other items like the single-piece letter and flat additional-ounce stamps had no price changes.

Summary of the 2023 Postage Rate Increase (Implemented July 9, 2023)

The following table summarizes the changes in postage prices and compares the new rates to the previous ones:

ProductPrevious pricePrice as of July 9, 2023
1oz letter$0.63$0.66
1oz letter (metered)$0.60$0.63
1oz flat$1.26$1.35
Additional-ounce stamp$0.24$0.24


  1. 48.9 B First-Class Mail volume
  2. Forever Stamp Fact Sheet
  3. First-Class Mail
  4. Price List
  5. First-Class Mail International
  6. The Postal Store
  7. Mail & Shipping Services
  8. Certified Mail® – The Basics
  9. USPS Ground Advantage™
  10. Postage Options
  11. International Mail & Shipping Services
  12. What Are You Mailing? Domestic
  13. Domestic Shipping Prohibitions, Restrictions, & HAZMAT
  14. Mailing & Shipping Prices