Direct Mail

What is Library Mail?

By 25 March 2024April 15th, 2024No Comments
usps library mail

What is Library Mail USPS?

Is it possible to send books, media materials, etc., via mail? The answer to the above question is a YES!

But wait… Can you send your items smoothly and affordably, too?

Luckily, the United States Postal Service offers a wide range of options for mailers to send different types of items. Followed by a perfectly efficient and on-time delivery!

usps library mail

As we mentioned in some of our previous blogs- First-Class Mail, Priority Mail, and Priority Mail Express are the most popular USPS options- The Services known for hassle-free mailing. 

But, the list of such services offered by the USPS does not end here. Yes, there are other services available too, like Media Mail and Library Mail. These options further help you send items that you cannot otherwise send using any other options.

In this blog, we will discuss everything about Library Mail. Keep reading further to also know the difference between Library Mail and Media Mail.

What Is Library Mail and How Long Does It Take to Arrive?

Library Mail is a cost-effective mailing solution for public libraries, museums, academic institutions, and other organizations. They can exchange specific items on loan with other institutions or send them to other destinations.

You can use Library Mail if you are either a qualified institution yourself or you want to mail to such an organization. For example, if you are a university, you can send educational materials to students or other universities through Library Mail.

You can send mailpieces like sound recordings, books, periodicals, and other library materials. Remember, every mail item should carry the name of a qualified organization in the mailing address or return address.

Library Mail items are subject to postal inspection if needed. The USPS workers can open and inspect your mail to check if the items are eligible for sending under this option.

Please note: You cannot send items containing advertising or marketing messages via Library Mail.

How long does USPS Library Mail take?

Now that depends on your mail destination- the USPS Library Mail delivery time is seven to ten business days.

The postage is based on the weight and size of your items. Generally, Library Mail rates are charged per fraction or pound—even a fraction of a pound makes one whole pound. For example, if your item weighs 5.89 pounds, the USPS considers it 6 pounds.

Mailers can only send items weighing up to 70 pounds via Library Mail and Media Mail.

Plus, all Library Mail materials must carry a delivery address with the correct ZIP and ZIP+4 codes. Don’t forget to add a return address as well.

USPS Library Mail Rates

If you are sending items having non-identical weights, you should weigh every piece individually. In this case, the postage for every mailpiece can be different.

For identical-weight items, weigh at least ten random pieces together and divide the total weight by the number of items in the sample group. The answer decides the postage of every item in your mailing.

There are two ways of paying postage for sending Library Mail, and they are:

Using Stamps

Every one-pound item needs one postage stamp. Hence, affix the correct number of stamps according to the weight of your materials.

Using Permit Imprints

If you don’t want to use stamps and prepay your postage, you can get a permit and print imprints on your items.

Postage rates for Library Mail depend on the weight of your materials, irrespective of where you are sending them. The rate discounts and categories are as follows:

5-Digit Rates

All items should be prepared and sorted as per the 5-digit scheme (only for machinable USPS Library Mail parcels). You can select between using 5-digit sacks and pallets.

Every 5-digit bundle on pallets should consist of at least ten items.

Nonmachinable pieces can qualify for 5-digit rates only when prepared for preserving sortation by the 5-digit ZIP codes. In such cases, you should follow the instructions and prescriptions of the Postmaster.

Basic Rates

If your USPS Library Mail packages are ineligible to mail at 5-digit rates, they automatically qualify for basic rates.

Nonmachinable items may also qualify for basic rates when prepared to preserve 5-digit sortation as prescribed by the Postmaster.

Barcode Discounts

Barcode discounts apply to Library Mail machinable parcels while mailing at least 50 pieces.

Also, your items must be posted at basic or single-piece rates and bear the correct barcodes for the delivery address ZIP codes.

Barcode discounts are not available for items charged at 5-digit rates.

Now, let us get to the Library Mail retail and commercial rates:

Weight not over (pounds) Single-Piece 5-Digit Presort Basic Presort
1 $3.03 $1.81 $2.82
5 $5.43 $4.21 $5.22
10 $8.43 $7.21 $8.22
15 $11.43 $10.21 $11.22
20 $14.43 $13.21 $14.22
25 $17.43 $16.21 $17.22
30 $20.43 $19.21 $20.22
35 $23.43 $22.21 $23.22
40 $26.43 $25.21 $26.22
45 $29.43 $28.21 $29.22
50 $32.43 $31.21 $32.22
55 $35.43 $34.21 $35.22
60 $38.43 $37.21 $38.22
65 $41.43 $40.21 $41.22
70 $44.43 $43.21 $44.22

Single-piece rates are only for retail mailers. They start at $3.03, and the USPS charges an extra $0.60 for every additional pound. 

Only commercial printed mailers can avail of the 5-digit and basic rates. But, they need to apply for a permit and pay an annual fee of $160 at the permit-issuing Post Office.

Who Can Send Library Mail?

The most crucial criteria for Library Mail USPS is that items should be sent to or from a university, public library, school, college, herbarium, museum, nonprofits, and similar organizations. Also, nonprofits should come under one of the following categories:

  • Philanthropic
  • Religious
  • Labor
  • Fraternal
  • Veterans
  • Scientific
  • Educational
  • Agricultural.

Pieces charged at Library Mail pricing can also be sent between:

  • Qualified associations or organizations and individuals have no financial interest in promoting, distributing, or selling the items.
  • Qualified organizations and publishers if the said organizations place an order for such materials.

Which Items Can You Send Using Library Mail?

Library Mail consists of items that:

  • It cannot be sent or doesn't need to be sent via First-Class Mail.
  • This mail type cannot be considered periodicals.

The below items can be sent at USPS Library rates:

  • Bound or unbound periodicals.
  • Sound recordings.
  • Books consisting of reading matter wholly or partially with incidental empty spaces for notations.
  • Scholarly bibliographies.
  • Printed music in sheet or bound form.
  • Bound volumes of academic thesis in duplicated or typewritten form.
  • Other library materials in photographic, duplicated, or printed form, or as unpublished manuscripts.
  • Printed matter, museum materials, teaching aids, collections, specimens, and interpretive items for assisting with the work of herbariums and museums.

All the materials that we listed above can be sent between qualified organizations—for example, one nonprofit mailing to another.

Here are the items that can be received from or sent to qualified institutions:

  • Mathematical or scientific kits, instruments, and other devices.
  • Museum materials, collections, specimens, printed matter intended to help with the educational work of museums and herbariums.
  • 16 mm or narrower film strips, films, slides, and microfilms. All of them should be positive prints in the final form.
  • Sound recordings.
  • Catalogs for all the above materials.
  • Guides and scripts are solely prepared for use with such items.

Library Mail Enclosures and Attachments

You can add some attachments with your USPS Library Mail items and not pay any extra postage for them.

Below are some types of mail pieces that you may attach to Library Mail:


You can place an invoice or bill inside Library Mail items or in envelopes marked “Invoice Enclosed.” Make sure to attach these envelopes to the outside of your items sturdily.

Such invoices should solely relate to the materials with which they are mailed.

Invoices may consist of the following details:

  • Names and mailing addresses of the recipient and sender.
  • Quantities, particulars, and description of the items- tax, price, stock number, quality, style, nature of any defects).
  • Date of order, current date, manner of shipment, postage paid, file or order number, packer’s name.

Incidental First-Class Mail

Incidental First-Class matter can be attached to or enclosed with Library Mail without paying the First-Class postage. It should be secondary to the host materials but closely related to them.

Also, mailers must ensure that such attachments or enclosures do not interfere with the items’ postal processing.

First-Class Mail can consist of:

  • Bills
  • Account statement for past purchases
  • Personal greetings attached to the mailpieces

The US Postal Service Library Rate is dependent on the combined weight of the attachment and the host item.

Enclosures in Sound Recordings and Books

Sound recordings and books can contain the following enclosures:

  • One addressed postcard or envelope that may or may not serve as an order form.
  • One order form that may or may not serve as an envelope or card.
  • Book announcements in book pages or in the form of loose enclosures. They should be exclusively devoted and incidental to books and not contain any advertising messages. Also, announcements can explain the methods and conditions of ordering books, like subscribing for membership in a book club.
  • Sound recording announcements can be printed or enclosed on protective sleeves, cartons, wrappers, title labels, or loose enclosures. They should be exclusively devoted and incidental to sound recordings. Avoid using enclosures and attachments that contain advertising of materials or services related to the sound recordings.

Books and sound recordings can also have attachments like incidental First-Class Mail matters and invoices.

Apart from enclosures and attachments, Library Mail can consist of some written additions. But, remember that you would need to pay extra First-Class postage for markings indicating personal correspondence.

The following written additions do not require you to pay additional postage:

  • The names of the sender and the addressee. You can also include their occupations below the names.
  • Mailing addresses that are preceded by the words “To” and “From.”
  • Directions for handling mail.
  • Phrases like “Happy Birthday Brother” and “Do Not Open Until Thanksgiving.”
  • Directions and instructions for using the materials mailed.
  • Manuscript inscriptions and dedications that don’t fall under the category of personal correspondence.
  • Marks are meant to call attention to specific passages or words in the text.
  • Typographical error corrections in printed matter.
  • Hand-stamped imprints, except when the added matter is personal or converts the host piece to personal correspondence.
  • Manuscripts with incidental proof sheets and the corrections of these sheets. Insertions of newly added text, typographical error corrections, corrective rewrites, marginal instructions for the printer, etc.
  • Standard Mail items are separately printed on an envelope, shipping label, tag, or wrapper.

Library Mail Additional Services

The USPS offers free tracking with Library Mail to enable you to know your mail delivery status in real-time.

All you have to do is keep the mailing receipt safe so that you can enter the number on the USPS website and check your mail status. Alternatively, you can also check the status via phone or text.

Apart from USPS tracking, mailers can opt for paid add-on services like Signature Confirmation, COD, Return Receipt, and additional insurance.

Availing of Signature Confirmation costs you $3.45 per piece, but it is worth it. Using this option, you can confirm that your mail was delivered and accepted accurately. It also serves as proof of delivery to the recipient’s address. This USPS service is helpful when you are mailing high-value or time-sensitive items.

The COD (Collect on Delivery) service can cost you anywhere between $8.60 to $31.85. It depends on the insurance coverage you need or the amount to be collected- whichever is higher.

Return Receipts cost $3.05, and you can request them while posting your items. If you want to keep the costs low, you can opt for an electronic Return Receipt at $1.85.

What Is Media Mail?

Many people think that Library Mail is the same thing as Media Mail. However, these options serve different purposes, though they have very similar features.

Media Mail items include small and large parcels containing:

  • Films, CDs, and DVDs
  • Video recordings
  • Printed music
  • Books (with at least eight pages)
  • Piano rolls
  • Sound recordings
  • Manuscripts and play scripts
  • Computer-readable media documents (should include digital versions of media materials, not other files or video games. 
  • Film reels
  • Printed educational materials
  • Medical information

The maximum weight limit of sending Media Mail items is 70 pounds. Also, like Library Mail, you cannot send advertising or promotional items.

Also, Media Mail does not include comic books, computer software, video games, graphic novels, magazines, etc. It is because Media Mail is used to send items of educational value and not entertainment.

The prime difference between Library Mail vs. Media Mail is that anyone can send Media Mail. On the contrary, only qualified institutions can send Library Mail. Also, it is a little more costly than Library Mail as USPS Media Mail rates start at $3.19 and range up to $46.66.

Again, commercial mailers can presort their items and get 5-digit and basic presort rates to bring down their postage.

However, it is sometimes hard to presort and prepare items according to the USPS requirements. Hence, you can use direct mail services like PostGrid to make your job easier and faster.

Our API can help you create, print, and mail marketing and transactional items. Plus, it can help you with other related tasks like mailing address verification, adding ZIP+4 codes, presorting, etc.


Library Mail is a USPS mail service that makes it easier for qualified institutions to send and receive crucial items easily and affordably. They can send educational mailpieces to their students, clients, etc., or to other organizations.

Although Library Mail and Media Mail take up to ten business days to arrive, they are much cheaper than other mailing options. Plus, they offer Signature Confirmation and other add-ons to make your deliveries secure.

Furthermore, PostGrid can assist you in the process and help you streamline your mailing activities. Request a demo now to know more about how we can help you send Library Mail!

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