Illegal stamps are those having the official name of legitimate country or territory, however they were not produced or issued either by the postal administration of a corresponding country or the authorized philatelic agents. Therefore, those postage stamps are not valid for postage anywhere in the world and cannot cover the costs of postal services in a corresponding country.

The postal administration and philatelic agent collaborate during all the stages of legal process of creating a postage stamp (e.g. creating a theme, making designs, circulation, denomination, ensuring quality, establishing the deadline, etc.). The obligation of postage stamps to be original and issued in a high quality falls under the philatelic agent responsibility.

Illegal stamps may look like very similar to the official stamps, however their producer is not authorized to issue them or breaches the contract with a corresponding country. Postal administrations do not acknowledge the afore-mentioned stamps, therefore they cannot cover the costs of postal services.

Illegal stamps circulating in the market are said to result in adverse consequences for several different parties. Postal administrations lose revenue to illegal issues and stamp collectors may lose money by mistakenly buying illegal stamps that have little or no monetary value.

In order not to be misled by fake stamps, you can always check the information about the official postage stamps in the websites of postal administrations, since they always make it public. The official stamps may also be found in the official websites and catalogues of authorized philatelic agents, for example, Yvert et Tellier (France), Michel (Germany), Scott (USA). Last but not least, you may also find the official postage stamps in the various philatelic periodicals. 

Fake stamps is not equal to illegal stamps.

There are many forms of illegal stamps. Some of them may be called “cinderella” stamps, meaning they are virtually anything resembling a postage stamp, but not issued for postal purposes by a government postal administration. You may also see the term “bogus stamp”, which means fictitious stamps which purport to be produced by an entity that exists and might have produced them, but did not. A bogus stamp is not a forgery because it is not based on any genuine stamp. It does not even resemble anything that the entity did produce, and only rarely are any of these labels ever shipped to the place that is shown as issuing them. The term also refers to a genuine stamp which bears the sham addition of an unauthorized surcharge or overprint. Another term describing illegal stamps is “fantasies” which are stamps issued by non-existing places.

Fake stamps are used to indicate the alteration of a genuine stamp to make it appear as something else. They are also known as forgery intended to defraud collectors or counterfeits intended to defraud stamp-issuing governments, both meaning the illegal copies of official stamps (this activity is regarded as a criminal offence in most of the countries).