Contents Index
M000 General Preparation Standards
M030 Containers

M033 Sacks and Trays

Summary

M033 describes the standards for sacks and trays, and the proper methods for preparing letter trays, flat trays, and sacks.

1.0 Basic Standards

1.1Maximum Weight

The maximum weight of any sack (mail plus sack tare) must not exceed 70 pounds.

1.2Standard Containers

Depending on the class of mail and processing category, mailings must be prepared in trays or sacks as shown in Exhibit 1.2 and under other applicable standards in this section. Containers for Customized MarketMail are specified in M660. Containers for Package Services mail are specified under the appropriate standards in M700. The following additional standards apply to Exhibit 1.2:

a. Letter-size mail for other classes of mail not shown in Exhibit 1.2 may be prepared in letter trays, subject to applicable preparation standards.

b. Palletized mail is also subject to M040.

c. A postmaster may authorize nonpostal containers for a small-volume presorted mailing if the mailing weighs no more than 20 pounds, consists primarily of mail or bundles of mail for local ZIP Codes, and requires no USPS transportation for processing.

Exhibit 1.2Standard Containers

Mail Class Processing Category USPS Container
First-Class Mail Letter-size Letter tray (with sleeve)
  Flat-size Flat tray (with green lid)
  Parcel Sack (green)
Priority Mail Letter-size, flat-size, parcel Sack (orange)
Periodicals Letter-size Letter tray (with sleeve)
  Flat-size, parcel (machinable and irregular), and letter-size not required in trays Sack (brown)
Standard Mail Letter-size Letter tray (with sleeve)
  Flat-size under M033 Letter tray (with sleeve)
  Flat-size except under M033, parcel (machinable and irregular) Sack (white)
  Customized MarketMail under M660 Letter tray (with sleeve), flat tray (with green lid inverted), white sack
1.3Tray Sizes

These approximate measurements define the tray sizes that apply to all mail preparation standards:

a. Letter trays:

(1) 2-foot managed mail (MM) trays: 21 inches long by 10 inches wide (inside bottom dimensions) by 4-5/8 inches high.

(2) 1-foot MM trays: 10-1/4 inches long by 10 inches wide (inside bottom dimensions) by 4-5/8 inches high.

(3) 2-foot extended MM (EMM) trays: 21-3/4 inches long by 11-1/2 inches wide (inside bottom dimensions) by 6-1/8 inches high.

b. Flat trays:

(1) Inside bottom dimensions: 14-3/4 inches long by 10-3/4 inches wide.

(2) Height: 8 inches to bottom of handhold, 11-1/4 inches to top of tray.

1.4Presort

Presort, presort levels, and standard preparation terms are defined in M011.

1.5Tray Sleeving and Strapping

Letter trays and flat trays are secured as follows, using USPS-provided sleeves or lids:

a. Each letter tray must be sleeved. Except under 1.6, each sleeved letter tray must then be secured with one plastic strap placed tightly around the length of the tray without crushing the tray or sleeve.

b. Each flat tray must be covered with a lid. Each covered flat tray must then be secured with two straps placed tightly around the width of the tray (i.e., the shorter dimension).

1.6Strapping Exception

Strapping is not required for any letter tray placed on a 5-digit, 3-digit, or SCF pallet secured with stretchwrap. In addition, if the processing and distribution manager gives a written waiver, strapping is not required for any mixed ADC or mixed AADC letter tray of First-Class Mail or for any letter tray that originates and destinates in the same SCF (mail processing plant) service area.

1.7Origin/Entry 3-Digit/Scheme
Trays and Sacks

Except for flat-size and irregular parcel-size Periodicals under 1.8, after all finer sort levels are prepared, an origin/entry 3-digit sack or tray (or, if applicable, origin/entry 3-digit scheme tray) must be prepared to contain any remaining mail for each 3-digit (or 3-digit scheme) area serviced by the SCF serving the post office where the mail is verified (origin), and may be prepared for each 3-digit (or 3-digit scheme) area served by the SCF/plant where mail is entered (if that is different from the SCF/plant serving the post office where the mail is verified—e.g., a PVDS deposit site). In all cases, only one less-than-full sack or tray may be prepared for each 3-digit (or 3-digit scheme) area.

1.8Periodicals Flats and Irregular Parcels Origin/Entry SCF Sacks

For flat-size and irregular parcel-size Periodicals, after all finer sort levels are prepared, an origin/entry SCF sack must be prepared to contain any remaining 5-digit and 3-digit bundles for the 3-digit ZIP Code area(s) served by the SCF serving the post office where the mail is verified (origin), and may be prepared for the area served by the SCF/plant where mail is entered (if that is different from the SCF/plant serving the post office where the mail is verified—e.g., a PVDS deposit site). In all cases, only one less-than-full sack may be prepared for each SCF area.

2.0 First-class Mail, Periodicals, and Standard Mail

2.1Letter Tray Preparation

Letter trays are prepared as follows:

a. Subject to availability of equipment, standard MM trays must be used for all letter-size mail, except that EMM trays must be used when available for letter-size mail that exceeds the inside dimensions of MM trays defined in 1.3. When EMM trays are not available for those larger pieces, they must be placed in MM trays, angled back, or placed upright perpendicular to the length of the tray in row(s) to preserve their orientation.

b. Pieces must be “faced” (oriented with all addresses in the same direction with the postage area in the upper right).

c. Each tray prepared must be filled before filling the next tray, with the contents in multiple trays relatively balanced. When preparing full trays, mailers must fill all possible 2-foot trays first; if there is mail remaining for the presort destination, mailers must use a combination of 1-foot and 2-foot trays that results in the fewest total number of trays for that presort level. As an alternative, if there is mail remaining, mailers may move those pieces to the next higher presort level at which there is a minimum quantity (e.g., 150 pieces).

d. For presort destinations that do not require full trays, pieces are placed in a less-than-full tray.

e. Mailers must use as few trays as possible without jeopardizing rate eligibility. For instance, a mailer will never have two 1-foot trays to a single destination; instead, that mail must be placed in a single 2-foot tray. A 1-foot tray is prepared only if it is a full tray with no overflow; or if there is less than 1 foot of mail for that destination; or if the overflow from a full 2-foot tray is less than 1 foot of mail.

f. Each tray must bear the correct tray label.

g. Each tray must be sleeved and strapped under 1.5 and 1.6.

h. If a mailing is prepared using an MLOCR/barcode sorter and is submitted with standardized documentation, then pieces do not have to be grouped by 3-digit ZIP Code prefix (or by 3-digit scheme, if applicable) in AADC trays, or by AADC in mixed AADC trays.

2.2Letter Tray Preparation
Standard Mail Flat-Size Pieces

Standard Mail flat-size pieces may be prepared in letter trays instead of sacks only if the following standards are met:

a. At least 90% of the mailing job must be claimed at automation rates or Enhanced Carrier Route rates. No more than 10% of the mailing job may be claimed at Presorted rates. As provided in E620, the following minimum volumes for Standard Mail must be met:

(1) For the portion claimed at automation nonletter rates, a separate 200-piece minimum must be met. For any portion of the job claimed at Presorted rates, no separate minimum is required.

(2) For any portion claimed at Enhanced Carrier Route nonletter rates, a separate 200-piece minimum must be met.

b. Automation rate pieces must meet the applicable flat-size dimensions in C820. Presorted and Enhanced Carrier Route pieces must meet the flat-size dimensions in C050.

c. The pieces must fit completely within the dimensions for height and the bottom (floor) dimensions for length and width specified in 1.3 for an MM letter tray or an EMM letter tray. If a single row of pieces is placed in a tray, all pieces must be upright, faced toward the end of the tray (the short dimension), and perpendicular to the length of the tray. If two rows of pieces are placed in a tray, the rows must be parallel to each other and to the length of the tray and all pieces must be upright, faced toward the end of the tray, and perpendicular to the length of the tray. Other applicable standards in 2.1 must also be met.

d. Trays must bear tray-size labels that meet all applicable physical and barcode standards under M032, with Line 1 and Line 2 information as required for flat-size mail in sacks. Each label must contain a barcode as specified in M032.2.4 and the content identifier number required in Exhibit M032.1.3a for the same type of flat-size mail prepared in sacks.

e. All mail prepared under M610, M620, or M820 must be bundled except for full 5-digit trays and full carrier route trays. The exception to bundling in M020 may be used for other sort levels. All mail prepared under M910 must be bundled.

f. All mail in the mailing job must be trayed. Sacking is not permitted except when the required minimum pallet load in M041.5.3 cannot be met.

g. All trays must be palletized under M045.3.2, except for mail prepared in trays for Priority Mail or Express Mail drop shipment or for mail prepared and claimed at Enhanced Carrier Route destination delivery unit rates. Trays of letter-size pieces must not be placed onto pallets with trays of flat-size pieces. Pallet labels must identify the mail as flat-size pieces.

h. All other applicable standards in M610, M620, M820, or M910 must be met, including required preparation sequence and use of sack minimums as tray minimums.

2.3Flat Tray Preparation (First-Class Mail Only)

All flat tray preparation is subject to these standards:

a. Addresses on all pieces must face upward in the same direction.

b. Pieces must be placed in trays to maintain their orientation. Once the required minimum volume is reached to allow or require preparation of a tray, additional pieces must be placed in the same tray up to its capacity to minimize the number of trays used. When possible, pieces must be placed in two or more stacks to optimize tray use, but mail must not overfill the tray to inhibit adequate closure or covering of the content.

c. The weight of a tray and its content must not exceed 70 pounds.

d. Each tray must bear the correct tray label.

e. Each tray must be covered (with the green side of the lid facing up) and strapped under 1.5 and 1.6.

f. For automation rate mailings prepared under the optional tray-based preparation rules in M820, one less-than-full overflow tray may be prepared for a presort destination when the total number of pieces for that destination meets the minimum for preparation of the tray level under M820, and when one or more full trays for that destination are also prepared.

g. For automation rate mailings prepared under the optional tray-based preparation rules in M820, if the total number of pieces for a presort destination meets or exceeds the minimum number of pieces required to prepare a tray for that destination, but the total volume does not physically fill a single tray, then the mail for that presort destination may be prepared in a less-than-full tray.

h. Pieces prepared as automation flats under the tray-based preparation option in M820 do not have to be grouped by 3-digit ZIP Code prefix in ADC trays or by ADC in mixed ADC trays if the mailing is prepared using an MLOCR/barcode sorter and standardized documentation is submitted.

2.4Sack Preparation

All sack preparation is subject to these standards:

a. Each sack must bear the correct sack label.

b. The weight of a sack and its content must not exceed 70 pounds.

DMM Issue 58 Updated 12-9-04