United States Postage Meter Stamp Catalog/Postage meters and mailing machines
Postage Meters and Mailing Machines
Starting in the early 1930s self-contained postage meters came into use. These meters were mostly fed by a hand-crank and included a bed or plate to back the mail piece while being franked. They were cheaper and suitable for low volume mailers. High volume mailers still required high speed mailing machines with detachable meters.
To prevent fraudulent use of postage meters they were required to contain two registers, one ascending and the other descending. The ascending register added the total of all postage generated by the meter. The descending register subtracted the postage generated from the dollar amount pre-paid by or credited to the meter user. The descending register would be re-set and re-sealed every time the meter user purchased more credit. This seal could be broken and replaced only when the meter was returned to the post office for resetting.
Many current meter models will take up to $9,999.99 worth of postage. The descending register indicates the total amount of postage remaining in the machine. When it reaches the maximum value that the meter will print in one stamp (usually $9.99 or $99.99) the meter locks, preventing further use until it is reset at the post office.
The ascending register is accessible only by postal security authorities. Periodically the ascending register is matched to the total credit purchased for the meter. Any discrepancy points to mechanical failure or potential fraud.