In
philately a backstamp is a
postmark
A postmark is a postal marking made on an envelope, parcel, postcard or the like, indicating the place, date and time that the item was delivered into the care of a postal service, or sometimes indicating where and when received or in transit ...
on the back of a
letter
Letter, letters, or literature may refer to:
Characters typeface
* Letter (alphabet), a character representing one or more of the sounds used in speech; any of the symbols of an alphabet.
* Letterform, the graphic form of a letter of the alphabe ...
showing a post office or station through which the item passed in transit.
The office of delivery may also backstamp a cover and this type of mark is known as a receiving mark.
Backstamps are often applied as documentation of transit times, lengthy ones in the case of ocean crossings or short ones in the case of
airmail
Airmail (or air mail) is a mail transport service branded and sold on the basis of at least one leg of its journey being by air. Airmail items typically arrive more quickly than surface mail, and usually cost more to send. Airmail may be t ...
flights.
Registered mail
Registered mail is a mail service offered by postal services in many countries which allows the sender proof of mailing via a mailing receipt and, upon request, electronic verification that an article was delivered or that a delivery attempt was ...
is often backstamped in order to show the
chain of custody
Chain of custody (CoC), in legal contexts, is the chronological documentation or paper trail that records the sequence of custody, control, transfer, analysis, and disposition of materials, including physical or electronic evidence. Of particula ...
.
Mail that has had complex routings can have a dozen or more backstamps. Although such covers may look positively blackened with the overlapping marks, they are not common and so are highly valued by collectors of
postal history, being described as "well travelled".
References
Philatelic terminology
Postal markings
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