What Is a Non-Machinable Stamp? | A Full Guide

What Is a Non-Machinable Stamp? | A Full Guide

Have you ever heard about the non-machinable stamp?

In most cases, the goods and mail reach their destinations through conveyor belts, scanners, and sorting devices.

But do you know that not all mail can traverse this automated wonderland smoothly? So a regular stamp isn’t suitable for this kind of mail. A non-machinable stamp is the one.

What exactly is a non-machinable stamp, you ask? What sets it apart from its machineable counterparts?

Congratulations! All your inquiries can get solved in this article. Read below!

What Is Non-Machinable Mail?

Before the non-machinable stamp, you need to know what non-machinable mail is.

Items that the postal system’s automated machinery cannot process and sort are known as non-machinable mail. These mailpieces, as opposed to their machinable equivalents, need special processing and are subject to extra fees because of their size, form, or weight.

Non-machinable mail demands manual processing to ensure its safe transit. Postal workers must handle these items individually, which is time-consuming and labor-intensive.

So, the non-machinable mail asks for an additional fee to cover the costs of manually sorting, processing, and delivering these items.

What Is the Difference Between Machinable and Non-Machinable Mail?

What Is the Difference Between Machinable and Non-Machinable Mail?

The distinction between machinable and non-machinable mail is based on their compatibility with automated postal processing.

Non-machinable mail necessitates manual handling and special treatment, whereas machinable mail is simple for machinery to sort and process.

Machinable mail meets specific criteria set by the postal service, such as size, shape, weight, and flexibility. Non-machinable mail, on the other hand, deviates from the set criteria and necessitates specific care during processing.

What Size Is Machinable Mail?

What Size Is Machinable Mail

Machinable mail should fall within the specified dimensions set by postal regulations. Machinable letters must not meet any of the non-machinable characteristics.


  • The minimum dimensions for letter-size pieces are 5 inches long, 3-1/2 inches high, and 0.007 inches thick. For letter-size pieces that are 0.009 inches thick, they must not exceed 4-1/4 inches in height, 6 inches in length, or both.
  • For First-Class Mail card prices, the maximum dimensions are 9 inches long, 6 inches high, and 0.016 inches thick.
  • The maximum dimensions for letters and other cards are 11-1/2 inches long, 6-1/8 inches high, and 1/4 inches thick.
  • These mailpieces should be rectangular, with four square corners and parallel opposite sides. If letter-size, card-type mailpieces are made of cardstock, their finished corners should have a radius that does not exceed 1/8 inch.

NOTE: Machinable mail may also have weight restrictions. Most types of mail have maximum weight limits to ensure the machines can handle the load.

What Is a Non-Machinable Stamp?

What Is a Non-Machinable Stamp?

This is the most important part!

A non-machinable stamp is a specific postage stamp that indicates that a mail item cannot be processed through automated sorting machines.

Non-machinable stamps are typically required for letters or packages that have irregular shapes, dimensions, or characteristics that prevent them from being sorted efficiently by machinery

Affixing a non-machinable stamp to such mail items alerts postal workers to handle them manually, ensuring proper processing and delivery. Non-machinable stamps often incur additional fees to account for the extra handling required.

How Do I Know if a Stamp Covers the “Non-machinable” Surcharge?

To determine if a stamp covers the “non-machinable” surcharge, consider these 2 factors:


Check the dimensions of your mail item. It will likely require additional postage if it exceeds the maximum dimensions the postal service sets.


Examine the shape of the item. Irregular shapes, rigid envelopes, or items with clasps, buttons, or strings may also incur the surcharge.

If your mail meets any of these criteria, it’s advisable to use a non-machinable stamp or consult the postal service for guidance.

Can I Use a Non-Machinable Stamp on Regular Mail?

In terms of postage rate, you can; but I would not recommend that.


  • Non-machinable stamps on mail items require special care. They cannot be sorted automatically, thus resulting in delays or incorrect processing, as they might be treated differently by the postal service.
  • A non-machinable stamp costs and covers more postage rate than regular mail. Hence it’s not worth it and unnecessary for regular mailing.

On These 5 Situations, Use A Non-Machinable Stamp

To be specific, when should you use a non-machinable stamp? Continue to read; here are 5 situations you should use non-machinable stamps:

  1. Square or Oversized Envelopes. Non-machinable stamps may be required if you send mail in square envelopes or envelopes that exceed the maximum size restrictions stipulated by postal rules.
  2. Rigid or Bulky Items. Rigid, inflexible, or bulky items can cause issues with the automated sorting equipment. Examples include pens, keys, lumpy packages, or uneven thicknesses. So, you should use a non-machinable stamp.
  3. Uneven or Non-Rectangular Thickness. If your mail piece has uneven thickness due to lumpy contents, clasps, or attachments, it may not be suitable for automated processing. Non-machinable stamps are needed.
  4. Sealed Polybags. Catalogs and brochures in polybags or plastic wrapping cannot be sorted. Non-machinable stamps can notify postal workers that particular mail pieces require manual handling.
  5. Oddly Shaped Items. Tubes and triangular packages, for example, are incompatible with automated sorting equipment because their shapes depart greatly from the normal rectangular envelope. Non-machinable stamps are required for proper processing.

How Much Does A Non-Machinable Stamp Cost?

How Much Does A Non-Machinable Stamp Cost?

As of July 2023, a 1-ounce First Class Non-Machinable stamp costs $1.06 after the most recent price rise.

This price includes a Non-Machinable surcharge and the cost of First-Class postage. The Non-Machinable surcharge costs $0.40. Therefore, a book of 20 Non-Machinable stamps will cost you $21.20.

Available Designs of Non-Machinable Stamps

Non-machinable stamps are often called butterfly stamps because they feature colorful butterfly stamps. These stamps feature the words Non-Machinable Surcharge and the USA printed on them.

Finally, let’s appreciate 3 beautiful non-machinable stamps together!

Colorado Hairstreak Butterfly Stamp

Add the beauty of the Colorado Hairstreak butterfly to your stamps collection with this 100-piece set of Forever stamps.

Colorado Hairstreak Butterfly Stamp is the ninth non-machinable stamp designed for oddly sized envelopes. They were available on March 9, 2021. These stamps are made for non-machinable mail, ensuring your valuable envelopes stand out while avoiding machine processing.

With their adhesive backing, they’re easy to affix to your envelopes. The words “NON-MACHINEABLE SURCHARGE” on the stamp indicate its usage value. This stamp will always be valid for its indicated rate as a Forever stamp.

California Dogface Butterfly Stamp

California Dogface Butterfly Postage Stamps

Designed to add a touch of beauty to your mail, these stamps feature the captivating California Dogface Butterfly, a symbol of grace and elegance. The California dogface butterfly was issued on 1/27/2019 as the seventh non-machineable stamp. They are carefully crafted to meet postal requirements for irregularly sized envelopes.

Eastern Tailed-Blue Butterfly Stamp

Eastern Tailed-Blue Butterfly Stamp

The Eastern Tailed-Blue Butterfly Stamp is a stunning addition to any philatelist’s collection. This elaborately created stamp depicts the exquisite elegance of the Eastern Tailed-Blue butterfly, native to North America.

It was released on September 24, 2016, highlighting nature’s magnificent beauty while having the practical goal of denoting non-machinable mail.



    John Thomas is a seasoned writer with a passion for stamps. Born and raised in a family of collectors, John grew up with a keen interest in philately. Over the years, he has honed his expertise in this field and has become an accomplished author of several books and articles on stamp collecting.

Leave a Reply

Your email address will not be published. Required fields are marked *