Customer Support Ruling
Determining the Classification of Mail: Host Piece Test
UPDATED July 2018
This CSR discusses the use of the "host piece test" when combining different classes of mail within a mailpiece.
When combining mail of different classes, it is necessary to determine the classification of mail for the mailpiece. This determination is based on the “host piece test,” which looks to the relative weights of the items in the mailpiece. The ”host piece test” is applicable for combination price mailings (e.g., First-Class Mail enclosed or attached in USPS Marketing Mail and Package Services, USPS Marketing Mail enclosed or attached in Package Services, USPS Marketing Mail enclosed or attached in Periodicals) as well as when mailing “permissible” enclosures or attachments with mail of a specific classification.
The “host piece test” is done as follows. The contents of the mailpiece are segregated by classification, with the packaging initially set aside. The grouping of items in each classification is weighed. The grouping that weighs the most is considered to be the “host piece” and the mailpiece is classified according to the classification of the items in the grouping. For postage purposes, the weight of the packaging is considered to be part of the host piece and postage on the remaining matter (i.e. items in other groupings) are paid according to the attachment, enclosure, and other standards governing the host piece.
At issue in this example are the Bound Printed Matter (BPM) prices. BPM may be mailed with “permissible” enclosures or attachments (see DMM 218.104.22.168) on which postage is paid at BPM prices; “nonpermissible” enclosures or attachments subject to USPS Marketing Mail prices (a mailing of mixed classes); or with a combination of both “permissible” enclosures or attachments and “nonpermissible” enclosures or attachments subject to USPS Marketing Mail prices (also a combination price mailing).
For example, the mailing in question consists of: two pieces of BPM each weighing one pound, packaging weighing 0.2 pounds, and three attachments or enclosures (consisting of printed matter mailable as USPS Marketing Mail and two “nonprint” attachments) weighing a total of 1.25 pounds. Since the weight of the BPM (two pounds) exceeds the weight of the attachments and enclosures (1.25 pounds), the host piece is BPM. The weight of the packaging is added to the BPM for postage payment purposes, so that the weight of the BPM is 2.2 pounds. In order to determine whether the attachments and enclosures are permissible or nonpermissible (and therefore whether their weight is added to that of the host piece for postage payment purposes or assessed postage separately at USPS Marketing Mail prices), the attachment/enclosure provisions of the host piece (i.e. BPM) must be applied.
If the BPM does not outweigh the attachments and/or enclosures in the example, BPM would not be considered the host piece. For instance, in the example above, suppose the combined weight of the attachments and enclosures is 2.25 pounds. Then the combined attachments and enclosures (2.25 pounds) would outweigh the BPM (2 pounds) and the host piece would not be BPM. In this instance, the mailpiece could be mailed at the applicable Priority Mail, USPS Retail Ground, or Package Services price, with that price applied to the entire weight of the mailpiece (including the packaging).
The same general guidelines for determining the host piece in the above example apply to other mailings with enclosures and mixed class mailings.