What is the work in process account used in job costing?

The work in process account acts like a holding account for the costs of products while they are in the process of being built or assembled. So, as pieces are added or labor is used to create a product, those costs are added to the work in process account. The work in process account is an asset on the balance sheet. The purpose of the work in process account is to comply the accounting principle of matching expenses with revenues. If the work in process account was not used the cost of components and direct labor would be expensed in one financial period and the sales revenue could possibly be recognized in a different period. That could be misleading to potential investors or creditors.