Postal Regulations for Folded Self-Mailers

Folded Self-Mailer Options

I often joke that you need a doctorate degree to understand the complex and constantly changing details of the Postal Service’s mailings regulations. While folded self-mailer regulations changed a few years ago, it is always good to get a refresher. A few years ago, regulations changed to make the process of high volume mail pieces more compatible with automation equipment, thus saving time and money for both you and the Post Office.

Here’s the skinny on the most recent folded self-mailer regulations:

First, a definition. A “folded self mailer” is a single sheet or multiple sheets of paper folded together without binding or stitching (with the exception of stitches on the inside folded edge). It qualifies for letter rates but isn’t mailed in an envelope and isn’t bound. To clarify, if it has staples in the fold or glue in the fold, it is defined by the Postal Service as a booklet and *not* a self-mailer.

The Postal Service grants automation (discounted) pricing for specific unenveloped mailpiece designs. However, Folded Self-Mailers (FSM) designs must meet required standards receive automation letter discounts.

Folded self-mailer stats to know when designing your mail:

  • Folds: Final fold must be on the bottom.
  • Tabbing: The folding configuration of the piece determines the location and quantity of wafer seals (or tabbing) required.  If tabs are used, a minimum of two is required. Tabs can no longer have perforations, and, based on weight, will require 1”, 1.5”, or 2” tabs
  • Size: The Aspect Ratio must be between 1.3 and 2.5 (length of piece divided by height). If you don’t comply with these new guidelines, your postage could double. More specifically, when a self-mailer is folded, it has to fall within the following dimensions:
    –Height: must be between 3.5″ and 6″
    Length/width: must be between 5″ and 10.5″
  • Weight: If the weight of the piece is less than one oz., it must be printed on at least 70 lb. paper stock. For pieces over one ounce the paper stock must be at least 80 lb. It can be no more than 3 oz. regardless of number of folds or paper weight.


For more folded self-mailer detailed information see the links below or email us at [email protected]:


  1. emily y lewis on July 5, 2018 at 3:00 pm


    I wanted to include a remittance envelope on the inside. Is that still allowed?

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