Jamaican Stamp Used Illegally -- I saw this cover with a stamp from Jamaica, used in the U. S. in 1920.

War Savings Stamp Illegally Used for Postage -- This is the image of a picture postcard that passed through the U.S. mails illegally in 1943. The reason for this is the use of a War Savings Stamp to pay the first class postage for the picture postcard. These savings stamps were supposed to be pasted into special books that could be exchanged for War Bonds, and were invalid for postage.

Revenue Stamp Illegally Used for Postage -- This is the image of the upper right corner of a cover that has passed through the U.S. mails illegally. The reason for this is the use of a revenue stamp to pay the first class postage for the letter. These stamps were supposed to be placed on legal documents as proof of payment of federal transaction fees, and were issued during the Spanish-American War. This stamp was used in 1899, after the War. Scott lists this stamp as number R164.

The cover itself is an ordinary business envelope, and shows no special markings that might indicate that it was mailed by a stamp collector, nor does it show any evidence of being intercepted by the Post Office.

Note that the stamp is cancelled by one of the many American Flag machines of Boston, Massachusetts. As described in my machine cancel pages, the American company manufactured a large number of machines that impressed the flag cancellation. Collectors find these markings on postal items from the late 19th through first third of the 20th centuries. However, note that Boston was the first major city to use this style of machine cancel.

llegal Use of Postage Due Stamp to Make Up War Rate -- This cover appears to have been accepted by the Post Office. This item is canceled in April of 1918, well after everyone knew that it would cost 3 cents to send a letter.

Apparently the sender decided that the "postage due" stamp was worth one cent postage. These stamps were supposed to be used only to show that postage had been paid upon receipt of a postage due item, not before mailing.

Savings Stamp Used for Postage (Modern) -- This cover shows the use of a Savings Stamp for postage. These stamps were supposed to be stuck in a savings folder and presented at the Post Office in exchange of a Savings Bond (or War Bond). I consider this a 'modern' usage (1961), while many of the other items on this page were used in the first part of the 20th century.

Illegal Use of Documentary (Revenue) Stamps -- This item was mailed with a pair of Revenue stamps (Documentary), instead of regular postage stamps. In this case, the illegal use was caught by the Post Office, and the recipient had to pay postage due.

Incorrect (Modern) Usage of a Postal Stationery Cutout -- When you buy pre-paid postal stationery, it is already imprinted by the required postage amount. This is called an 'indicia'. That indicia cannot be used to pay postage for anything else. However, people cut the indicia out of the envelope or postcard and stick it on another item for mailing. This is improper use of the indicia.

I note this as 'modern' because many of the other incorrect or illegal items shown on this page are from the first part of the 20th century.

A closeup image of the cutout follows:

Charity Stamp Used as Postage (Modern) -- Charity stamps, such as Christmas Seals are not actual postage. However, someone stuck one on an envelope, and it appears that this illegal use was not noticed by the Post Office.