the Classification of Mail: Host Piece Test
Revised July 2001
This Customer Support Ruling 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 rate mailings (e.g., First-Class Mail enclosed
or attached in Standard Mail and Package Services, Standard Mail enclosed or attached
in Package Services, Standard 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) rates. BPM may be mailed with “permissible”
enclosures or attachments (see DMM 4126.96.36.199) on which postage is paid at BPM rates;
“nonpermissible” enclosures or attachments subject to Standard Mail
rates (a mailing of mixed classes); or with a combination of both “permissible”
enclosures or attachments and “nonpermissible” enclosures or attachments
subject to Standard Mail rates (also a combination rate 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 Standard
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 Standard Mail
rates), the attachment/enclosure provisions of the host piece (i.e. BPM) must be
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 two and a quarter 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
Package Services (i.e. Parcel Post) rate, with that rate 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.
United States Postal Service
Washington DC 20260-3436