The Internal Revenue Service (IRS) considers bartering a form of revenue and something that must be reported as taxable income. Under U.S. generally accepted accounting principles, or GAAP, businesses are expected to estimate the fair market value of their bartered goods or services. This is done by referring to past cash transactions of similar goods or services and using that historical revenue as a reportable value. When it is not possible to accurately calculate the value, most bartered goods are reported based on their carrying value.

mid-15c., apparently from Old French barater "to barter, cheat, deceive, haggle" (also, "to have sexual intercourse"), 12c., of uncertain origin, perhaps from a Celtic language (cf. Irish brath "treachery"). Connection between "trading" and "cheating" exists in several languages. Related: Bartered; bartering. The noun is first recorded 1590s, from the verb. 

Adam Smith, the father of modern economics, sought to demonstrate that markets (and economies) pre-existed the state, and hence should be free of government regulation[citation needed]. He argued (against conventional wisdom) that money was not the creation of governments. Markets emerged, in his view, out of the division of labour, by which individuals began to specialize in specific crafts and hence had to depend on others for subsistence goods. These goods were first exchanged by barter. Specialization depended on trade, but was hindered by the "double coincidence of wants" which barter requires, i.e., for the exchange to occur, each participant must want what the other has. To complete this hypothetical history, craftsmen would stockpile one particular good, be it salt or metal, that they thought no one would refuse. This is the origin of money according to Smith. Money, as a universally desired medium of exchange, allows each half of the transaction to be separated.[3] 

If you've ever swapped one of your toys with a friend in return for one of their toys, you have bartered. Bartering is trading services or goods with another person when there is no money involved. This type of exchange was relied upon by early civilizations. There are even cultures within modern society who still rely on this type of exchange. Bartering has been around for a very long time, however, it's not necessarily something that an economy or society has relied solely on.
Since the latest series of worldwide economic meltdowns, people have bartered in growing numbers. Last year, the 100 members of the International Reciprocal Trade Association, a network of barter and trade exchanges, facilitated the bartering of billions of dollars’ worth of goods and services around the world. (The IRTA uses its own barter currency called Universal Currency.) In some areas of Greece, bartering has become as second nature as paying for things with cash—there’s even a new barter-style currency called the TEM, accrued through offering goods and services via a vast online network and regular open-air market days. Spain’s time bank system, in which people exchange hours of labour instead of units of currency, has grown exponentially as a result of the country’s crippled economy.