New USPS rule for First-Class Mail International Flats

Woman receiving a large envelope

First-Class Mail International (FCMI) has been a great low-cost option for sending letters, postcards and large envelopes—also known as flats—that do not require expedited delivery or tracking information. However, due to a new USPS rule going into effect soon, this option may no longer be available based on what you’re sending in those flats.

In order to comply with standards established by the Universal Postal Union, as of January 21, 2018 the USPS will only allow you to use First-Class Mail International flats to ship documents. In other words, you won’t be able to directly ship merchandise using FCMI flats.

What can I send?

Along with personal correspondence, here are some of the non-dutiable documents that are still OK to ship using FCMI flats:

  • Advertisements
  • Business and audit records
  • Circulars
  • Pamphlets
  • Written instruments not intended for resale

You can also use FCMI flats to send checks, money orders and other similar items that can’t be negotiated or converted into cash without forgery.

What can’t I send?  

Effective Jan. 21, dutiable goods the USPS will no longer allow to be shipped with FCMI flats include:

  • Artwork
  • Books
  • Collector or antique document items
  • Commercial photographs
  • Commercial engineering drawings and blueprints
  • Film, negatives and separation negatives
  • Periodicals
  • Printed educational or test materials
  • Printed music and player piano rolls
  • X-rays

Also on the merchandise list are digital and electronic storage media and devices such as CDs, DVDs and flash drives. This is regardless of whether they’re blank or contain electronic documents or other prerecorded media.

These merchandise items are required to bear a customs declaration form and will instead be eligible for First-Class Package International Service (or other available service). This will impact shippers currently relying on First-Class Package International flats, as the cost to ship with First-Class Package International Service is higher. The chart below provides a cost comparison between First-Class Mail International Flats and First Class Package International Service items going from the U.S. to Canada. The amounts in red reflect the price increase you’ll experience when shipping merchandise with First Class Package International Service, effective Jan. 21, 2018—for example, it will cost $10.41 more to ship a 15-ounce package containing merchandise as of Jan. 21.

Endicia can help!

Endicia offers a new service that will essentially let you keep the benefits (and lower pricing) of shipping with First-Class Mail International flats, without requiring you to print out customs forms. Contact us to learn more.

About Endicia

Endicia is a leading provider of internet-based postage services that make it easier and more affordable to ship parcels through the U.S. Postal Service®. We know that shipping can be complex and our goal is to simplify your shipping operations so you can focus on doing what you do best. Visit us at to learn more.

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323 N. Mathilda Avenue
Sunnyvale, CA 94085-4207



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