Private cancellations are cancellations of postage stamp

Postage stamp

A postage stamp is a small piece of paper that is purchased and displayed on an item of mail as evidence of payment of postage. Typically, stamps are made from special paper, with a national designation and denomination on the face, and a gum adhesive on the reverse side...

s, or, in some cases, artistamp

Artistamp

The term artistamp or artist's stamp refers to a postage stamp-like art form used to depict or commemorate any subject its creator chooses...

s, applied by other than a government or other official stamp-issuing entity. Private postmarks are commonly used with private postal meters, but in the United States there is a rule that if the time of posting is significant and there is both a private and regular cancellation, the regular cancellation controls.http://www.irs.gov/pub/lanoa/pmta01576_7400.pdf Private postmarks are also not considered in some other cases.http://oah.dc.gov/oah/frames.asp?doc=/oah/lib/oah/pdf/information/ui_faqs.pdf

They are also occasionally used to create first day of issue

First day of issue

A First Day of Issue Cover or First Day Cover is a postage stamp on a cover, postal card or stamped envelope franked on the first day the issue is authorized for use within the country or territory of the stamp-issuing authority. Sometimes the issue is made from a temporary or permanent foreign or...

s for personalized U.S. postage (officially defined as meter labels and thus not requiring cancellation).http://www.cart.c3cachets.com/product_info.php?cPath=107&products_id=1433&osCsid=55ac85c6f5d2c48710b78372fb97a00b Private cancellations are often applied by local post

Local post

A local post is a mail service that operates only within a limited geographical area, typically a city or a single transportation route. Historically, some local posts have been operated by governments, while others, known as private local posts have been for-profit companies...

s to their stamps (there are frequently also first day of issues of these).

Another type of private cancellation, in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, is the Mailer's Postmark Permit, by which licence-holders can cancel their own mail under certain conditions. They can also, in the U.S., be applied to mail

Mail

Mail, or post, is a system for transporting letters and other tangible objects: written documents, typically enclosed in envelopes, and also small packages are delivered to destinations around the world. Anything sent through the postal system is called mail or post.In principle, a postal service...

 carried outside the post by authority of the private express statutes

Private Express Statutes

The Private Express Statutes are a group of United States federal civil and criminal laws placing various restrictions on the carriage and delivery of letters by all organizations other than the United States Postal Service.-History:...

. An example of this is the Chickensville Location, Michigan

Torch Lake Township, Houghton County, Michigan

Torch Lake Township is a civil township of Houghton County in the U.S. state of Michigan. As of the 2000 census, the township population was 1,860.-Communities:...

private cancellation, applied to mail so carried although Chickensville Location does not have a post office.

Private postmarks have also been used (as backstamps) showing the name, presumably, of the firm from which the mail was posted.http://www.cdncovers.com/763usfancy.jpg

In Britain private cancellations can be seen on Phil Stamp's covers.