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Quick Service Guide 301a

Discount Flats

Designing Flats for Automated Processing

July 2007
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Related QSGs

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301, Physical Standards for Discount Flats

330b, First-Class Mail Automation Flats

340b, Standard Mail Automation Flats

360, Bound Printed Matter Flats

707g, Periodicals Machinable Flats


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Flat-size pieces meeting the applicable automation standards in 301.3.0 are entitled to automation or Periodicals machinable rates. Size, weight, thickness, polywrap, and flexibility standards vary for the class of mail. For eligibility and preparation standards for specific rate discounts, see the appropriate Quick Service Guide above.

Physical Standards (301.3.0)

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Shape: rectangular, with four square corners, or with finished corners that do not excced a radius of 0.125 inch (1/8 inch).


  • Minimum height is 5 inches. Maximum height is 12 inches.
  • Minimum length is 6 inches. Maximum length is 15 inches.
  • For bound or folded pieces, the edge perpendicular to the bound edge or folded edge may not exceed 12 inches.
  • Minimum thickness is 0.009 inch. Maximum thickness is 0.75 inch.

The length of a flat-size mailpiece is the longest dimension. The height is the dimension perpendicular to the length (301.1.2).

Maximum weight:

  • First-Class Mail: 13 ounces.
  • Periodicals: 20 ounces for pieces prepared under 301.3.0.
  • Standard Mail: less than 16 ounces.
  • Bound Printed Matter: 20 ounces.

Uniform thickness: The contents must be uniformly thick so that any bumps, protrusions, or irregularities do not cause more than 1/4 inch variance in thickness. The mailpiece must have a smooth and regular shape and be free of creases, folds, tears, or other irregularities (301.3.6).

Flexibility and deflection: automation flats must meet the flexibility standards in 301.1.3 and deflection standards in 301.3.2.3.

Polywrap films and similar coverings must meet the standards in 301.3.3. A list of approved polywrap and polywrap manufacturers is available on The wrap direction must be around the longer axis of the mailpiece, with the seam parallel to that axis. The longer axis is always parallel to the length of the mailpiece. The preferred seam placement is on the nonaddressed side of the mailpiece.

Prohibitions: Clasps, strings, buttons, or other protrusions; also staples, unless properly used as a binding method (301.3.6).

Barcodes (302.4.0)

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Barcodes must be at least 1/8 inch from any edge of the address side.

Address block barcodes must be in one of these four positions:

  • Above the address line containing the recipient's name.
  • Below the city, state, and ZIP Code line.
  • Above or below the keyline information.
  • Above or below the optional endorsement line.

The surface the barcode is printed on must meet the reflectance standards in 708.4.4.

Flat-Size Booklet-Type Mailpieces (301.3.6.3)

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The contents of the mailpiece prepared in sleeves or other wrappers must be sufficiently secure in the sleeve or wrapper to stay in place during processing. If material bearing the delivery information or barcode for the mailpiece is enclosed in a partial wrapper, that wrapper must be sufficiently secure to prevent the contents from shifting and obscuring the delivery address or barcode.

For the specific DMM standards applicable to this category of mail, consult the DMM sections referenced above and the general sections within each DMM module.

First-Class Mail, Standard Mail, Bound Printed Matter, and Periodicals (301.3.0)

This graphic shows the physical standards for Automated Flat Processing as described in the text.

Minimum: 6 inches
Maximum: 15 inches
Minimum: 5 inches
Maximum: 12 inches
Minimum: 0.009 inch
Maximum: 3/4 inch
Maximum Weight
  • First-Class Mail cannot weigh more than 13 ounces.
  • Standard Mail must weigh less than 16 ounces.
  • Periodicals and Bound Printed Matter cannot weigh more than 20 ounces.
Must meet flexibility standards in 301.1.3 and deflection standards in 301.3.2.3.
Polywrapped Pieces
Must meet all six properties in Exhibit 301.3.3.1.
If an address label is used on the outside of the polywrapped piece, the haze property is not required. Polywrap seam must be parallel to longest dimension.
The preferred seam placement is on the nonaddressed side of the mailpiece. If seam is on the addressed side, it must not cover the delivery address, barcode, postage area, or any required markings.


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