Postal Note stamps were first introduced on February 1, 1945. They were used in a similar manner to money orders to send smaller amounts of money to anyone in the mainland Unites States. The cost to send a smaller-valued money order was relatively high, so postal notes gave customers a cheaper option.
In all, the stamps came in 18 denominations, while the postal notes were printed in 11 denominations. People could use up to two stamps per note to pay between 1¢ and $1. They could also insure their notes for a fee of 5¢.
Postal Note stamps could only be used at specific post offices. The service was discontinued on March 31, 1951.