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401 Physical Standards

1.0 Physical Standards for Parcels

1.1 Processing Categories

USPS categorizes parcels into one of three mail processing categories: machinable, irregular, or outside parcel. These categories are based on the physical dimensions of the piece, regardless of the placement (orientation) of the delivery address on the piece.

1.2 Minimum Size

Pieces are subject to the minimum standards in 601.1.0, and may be subject to other minimum dimensions, based on the standards for specific prices.

1.3 Maximum Weight and Size

No mailpiece may weigh more than 70 pounds. Lower weight limits apply to parcels mailed at Priority Mail commercial plus cubic, Regional Rate Box, First-Class Package Service, Standard Mail, and Bound Printed Matter prices. Pieces may not measure more than 108 inches in length and girth combined, except Parcel Select. Standard Mail Marketing parcels (see 2.4) may not be larger than 12 inches long, 9 inches high, and 2 inches thick. Parcel Select parcels may not measure more than 130 inches in length and girth combined. For parcels, length is the distance of the longest dimension and girth is the distance around the thickest part. Lower size or weight standards apply to mail addressed to some APOs and FPOs subject to 703.2.0 and 703.4.0 and for Department of State mail, subject to 703.3.0.

1.4 Two or More Packages

Two or more packages may be mailed as a single parcel if they are about the same size or shape, are securely wrapped or fastened together, and do not exceed the weight or size limits.

1.5 Machinable Parcels

1.5.1 Criteria

A machinable parcel is any piece that is not a letter or a flat and that is (see Exhibit 1.5.1):

a. Not less than 6 inches long, 3 inches high, 1/4 inch thick, and 6 ounces in weight, except under 1.5.2. A mailpiece exactly 1/4 inch thick is subject to the 3 1/2-inch height minimum under 601.1.0.

b. Not more than 27 inches long, or 17 inches high, or 17 inches thick. Parcels cannot weigh more than 25 pounds, except Parcel Select and Parcel Return parcels which have a maximum weight of 35 pounds, except for those containing books or other printed matter (25 pound maximum).

Exhibit 1.5.1 Machinable Parcel Dimensions

Shows the dimensions for letter-size mail, flat-size mail, and machinable parcels.

1.5.2 Criteria for Lightweight Machinable Parcels

A parcel that weighs less than 6 ounces (but not less than 3.5 ounces) is machinable if it meets all of the following conditions:

a. The mailpiece is rectangular and able to maintain its integrity during mail processing (see 601.4.0).

b. Mailpieces weighing at least 3.5 ounces but less than 5 ounces must be a paperboard or fiberboard box within the following dimensions:

1. At least 1.5 inches thick and no more than 3 inches thick.

2. At least 6 inches long and no more than 7 inches long.

3. At least 3.5 inches high and no more than 5 inches high.

c. Mailpieces weighing at least 5 ounces but less than 6 ounces must be within the following dimensions:

1. More than 3/4 inch thick and no more than 6 inches thick.

2. At least 6 inches long and no more than 12 inches long.

3. At least 3-1/2 inches high and no more than 9 inches high.

1.5.3 Soft Goods and Enveloped Printed Matter

Soft goods wrapped in paper or plastic bags and enveloped printed matter are machinable only if all packaging standards in 601 are met.

1.5.4 Exception

Mailers of parcels that do not conform to the machinability criteria in 1.5.1 or 1.5.2 may request authorization to mail such parcels as machinable parcels by contacting the manager, Pricing and Classification Service Center (PCSC; see 608.8.1 for address). The manager, PCSC, in conjunction with the manager, Operations Integration and Support, may authorize such parcels as machinable if the parcels are tested on NDC parcel sorters and prove to be machinable. Mailers requesting testing of parcels for machinability must:

a. Submit a written request and two sample parcels to the PCSC. The request must list the mailpiece characteristics for every shape, weight, construction, and size to be considered. If the request describes a mailpiece that falls within the specifications of pieces that were tested previously, the mailpiece may not require testing.

b. State the estimated number of parcels to be mailed in the next 12 months, and the anticipated preparation level (e.g., destination NDC pallets).

c. Upon acknowledgement from the manager, Operations Integration and Support, the mailer may be required to send 100 mailpiece samples to the designated test facility at least 6 weeks prior to the first mailing date. The USPS may recommend changes to physical characteristics of the mailpieces, and additional testing of the redesigned pieces, before authorizing parcels as machinable.

1.6 Irregular Parcel

An irregular parcel is a parcel not meeting the dimensional criteria in 1.5.1 or 1.5.2. This processing category also includes parcels that cannot be processed by NDC parcel sorters, including rolls and tubes up to 26 inches long; merchandise samples that are not individually addressed and are not letter-size or flat-size; unwrapped, paper-wrapped, or sleeve-wrapped articles that are not letter-size or flat-size; and articles enclosed in envelopes that are not letter-size, flat-size, or machinable parcels.

1.7 Outside Parcel

An outside parcel is a parcel that exceeds any of the maximum dimensions for a machinable parcel. This processing category also includes high-density parcels (other than books and printed matter) weighing more than 15 pounds and exerting more than 60 pounds per square foot (0.4167 pound per square inch) pressure on their smallest side; cartons containing more than 24 ounces of liquid in one or more glass containers; cartons containing 1 gallon or more of liquid in metal or plastic containers; cans, paints; rolls and tubes longer than 26 inches; metal-band strapped boxes, metal boxes, and wood boxes; articles not mailed in boxes or other containers; harmful matter; hazardous materials except ORM-D materials; and containers with all dimensions exceeding the minimum dimensions for a machinable (regular) parcel, if their coefficient of friction or ability to slide on a smooth, hard surface is not similar to that of a domestic-class fiberboard box of the same approximate size and weight.

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2.0 Additional Physical Standards by Class of Mail

2.1 Priority Mail Express

2.1.1 Physical Standards of Mailpieces

Each piece of Priority Mail Express may not weigh more than 70 pounds. The combined length and girth of a piece (the length of its longest side plus the distance around its thickest part) may not exceed 108 inches. Lower size or weight standards apply to Priority Mail Express addressed to certain APO/FPO and DPOs. Priority Mail Express items must be large enough to hold the required mailing labels and indicia on a single optical plane without bending or folding.

2.1.2 Two or More Packages

With the exception of USPS-produced Priority Mail Express Flat Rate Envelopes, two or more packages may be mailed as a single parcel if they are about the same size or shape, are securely wrapped or fastened together, and when packaged as a single parcel do not exceed the weight or size limits.

2.2 Priority Mail

2.2.1 Physical Standards of Mailpieces

The maximum weight is 70 pounds, except for Commercial Plus Cubic (20 pounds); Regional Rate “Box A” (15 pounds); and Regional Rate “Box B” (20 pounds) parcels. The combined length and girth of a piece (the length of its longest side plus the distance around its thickest part) may not exceed 108 inches. Lower size and weight standards apply for some APO/FPO and DPO mail subject to 703.2.0, and 703.4.0, and for Department of State mail subject to 703.3.0.

2.2.2 Two or More Packages

With the exception of USPS-produced Priority Mail Flat Rate Envelopes or boxes, two or more packages may be mailed as a single parcel if they are about the same size or shape, are securely wrapped or fastened together, and when packaged as a single parcel do not exceed the weight or size limits.

2.2.3 Balloon Price

Pieces addressed for delivery to zones 1-4 (including local) and weighing less than 20 pounds but measuring more than 84 inches in combined length and girth are charged the price for a 20-pound parcel for the zone to which it is addressed. See 423.1.5.

2.2.4 Dimensional Weight Price

Postage for parcels addressed for delivery to zones 5-9 and exceeding 1 cubic foot (1,728 cubic inches) is based on the actual weight or the dimensional weight (see 423.1.6), whichever is greater.

2.3 First-Class Package Service Parcels

2.3.1 Weight

First-Class Package Service parcels cannot exceed 13 ounces, except for commercial plus parcels, which may exceed 13 ounces but must weigh less than 16 ounces.

2.3.2 Additional Physical Standards

The address side of the parcel must be large enough to contain all delivery and return address, endorsement, postage, and label elements. First-Class Package Service parcels are eligible for USPS Tracking and Signature Confirmation services. A First-Class Package Service parcel is:

a. A mailpiece that exceeds any one of the maximum dimensions for a flat (large envelope). See 101.2.1.

b. A flat-size mailpiece, regardless of thickness, that is rigid or nonrectangular.

c. A flat-size mailpiece that is not uniformly thick (has bumps, protrusions, or other irregularities that cause the thickness to vary more than 1/4 inch).

2.4 Standard Mail Parcels

2.4.1 Additional Physical Standards

Each piece must weigh less than 16 ounces.

2.4.2 Marketing Parcels

Marketing parcels do not meet letters or flats standards and have the following characteristics:

a. Height not more than 9 inches high. Minimum height must be 3-1/2 inches if the parcel is 1/4 inch thick or less.

b. Length not more than 12 inches long. Minimum length must be 5 inches if the parcel is 1/4 inch thick or less.

c. Thickness at least 0.009 thick, but not more than 2 inches.

d. An alternative addressing format, according to 602.3.0.

e. Marketing parcels mailed as small Product Samples under 443 must be no larger than 6 inches long, 4 inches high and 1.5 inches thick. Product Samples that have any dimension larger than one of the maximum dimensions for a small Product Sample, up to the maximum size in 2.4.2b. are large Product Samples.

2.5 Parcel Select

2.5.1 General Standards

These standards apply to Parcel Select:

a. Parcel Select pieces measuring over 108 inches in combined length and girth, but not more than 130 inches in combined length and girth, are mailable at the applicable oversized price.

b. An item weighing less than 20 pounds but measuring more than 84 inches (but not more than 108 inches) in combined length and girth is charged the price for a 20-pound parcel for the zone to which it is addressed (balloon price).

2.5.2 Nonmachinable Parcel Select

Mailpieces sent at Parcel Select Destination Entry prices are subject to the applicable nonmachinable prices in 453.1.0, except for parcels paying oversized prices (see 2.5.1a.) or parcels for which the special handling fee is paid. There are no nonmachinable prices for Parcel Select NDC Presort and ONDC Presort parcels. Mailpieces are nonmachinable if they meet any of the following criteria:

a. A parcel more than 27 inches long, 17 inches wide, or 17 inches high.

b. A parcel less than 6 inches long, 1/4 inch thick, or 3 inches high.

c. A parcel that weighs less than 6 ounces or more than 35 pounds, except under 1.5.2 for lightweight parcels.

d. A parcel containing more than 24 ounces of liquid in glass containers, or 1 gallon or more of liquid in metal or plastic containers.

e. An insecurely wrapped or metal-banded parcel.

f. A can, roll, or tube, or wooden or metal box.

g. Books, printed matter, or business forms weighing more than 25 pounds.

h. A high-density parcel weighing more than 15 pounds and exerting more than 60 pounds per-square-foot pressure on its smallest side.

i. A film case weighing more than 5 pounds or with strap-type closures, except any film case the USPS authorizes to be entered as a machinable parcel under 1.0 and to be identified by the words “Machinable in United States Postal Service Equipment” permanently attached as a nontransferable decal in the lower right corner of the case.

j. Parcels with characteristics (such as inadequate packaging) that could result in damage to the contents of the mailpiece, other parcels, or postal machinery if mechanical sortation is used.

2.5.3 Parcel Select Lightweight

Parcel Select Lightweight pieces must weigh less than 16 ounces, cannot exceed 108 inches in combined length and girth, and must be large enough to accommodate postage and other required elements on the address side of the piece.

2.6 Bound Printed Matter Parcels

2.6.1 General Standards

Pieces mailed at Bound Printed Matter prices may not weigh more than 15 pounds.