That depends on the specific stamps you are referring to. They can vary greatly based on age, condition and country. Consult a postage stamp catalog, such as Scott's or Gibbon's, and look for the postage due stamps in the 'back of the book' for the country in question. They are normally designated with a J in front of the number in Scott's.
They are still valid for use as postage as long as they add up to the proper postage. If you check USPS regulations Postage due, special delivery and certified mail stamps are NOT valid as payment for postage.
As long as it meets the postage due, it can be done with a single stamp.
Back of the Book stamps are those that are used for special purposes. These include Air Mail stamps, Special Delivery stamps, tax, official, and postage due stamps. In stamp albums and catalogs they are found at the 'back of the book.'
It is BUT the machines that read the stamps might show it as being cancelled and it could be returned to sender or be presented as postage due.
One if it is for the correct amount or greater in postage due.
The value of a 4 cent black and white Freedom of the Press US postage stamp depends on its condition, rarity, and demand among collectors. In general, most stamps from that era are valued at less than face value due to their common nature.
Use the postage calculator on the USPS website to figure out the first class postage due for the weight of your envelope, then divide by the current first class stamp price, then round up to determine how many forever stamps to use. As of 4/2009, forever stamps are worth $0.42 each, but their value will increase to $0.44 next month when postage goes up.
One if the amount is correct or greater than the postage due.
It will be posted if the postage due is exceeded. No refunds, no credit vouchers are extended. If you put too much postage on that is just tough.
B.O.B. stands for 'back of the book". The name comes from the way the catalogs list stamps. Stamps issued for special purposes such as air mail, special delivery, postage due collection, tax collection, official government mail, military post offices and other things, are listed behind the regular postage stamps and given special catalog numbers.
{| |- | Scott Number J95. This was issued in 1959. You can purchase one of these for 20 cents used and mint from a dealer. This minimum value indicates that it has no real value. Consult a stamp catalog such as Scott's, for a description on how stamps are rated and graded. |}
Brazil was the second country to use adhesive postage stamps, issuing its first stamp in 1843. The stamp was known as the "Bull's Eye" due to its design.