How are postage stamps canceled by postal services?

Postal services cancel postage stamps to prevent their reuse, typically using automated equipment or manual methods.

Automated Cancellation

Modern postal systems utilize facer-canceler machines to process mail efficiently. The process begins with "facing," where letters are aligned so that the address side faces the canceler and stamps are in a uniform position. These machines use sensing units to detect the presence and location of a stamp on an envelope. This detection is often facilitated by ultraviolet radiation that reacts to phosphorescent or luminescent inks printed on the stamps. Once identified, the machine applies a postmark, which serves as an official mark indicating the date and location of mailing.12

Manual and Alternative Methods

While most standard letters are processed by machines, items that cannot be handled by automated equipment—such as small parcels or oversized envelopes—are often sorted and stamped manually. Historically, or in specific cases where machinery is not used, a pen cancellation may be applied by hand. Additionally, a fiscal cancellation is used specifically to mark a stamp that has been utilized for revenue purposes.345