The first urbanization was taken place during the Indus Valley phase & some urban centers came into existence. The surplus production of raw material & finished goods, led to Barter System. The huge granaries found in the cities of Harappa & Mohenjo-Daro were replenished by the system of State tribute & served the purpose of modern State Bank. A large number of stone weights following a weight system, unit of which was 13 grains have been discovered which are multiples of 2, 4, 8, 10 etc. of this unit.
The bronze/copper seals bearing different motifs and animal figurines are under debate since long. These seals carry a pictographic script which is still enigmatic and undecipherable. Some archeologists argue about their motive and are of the view that they were used as currency.
These intricately carved seals are usually square to rectangular, 2-3 centimeters on sides, differ in sizes. These seals depict animals, mostly Indus script. These seals could potentially be one way of marking the property and monitoring the movement of assets between owner and entities.