The man who arguably founded modern economic theory, the 18th-century Scottish philosopher Adam Smith, popularized the idea that barter was a precursor to money. In The Wealth of Nations, he describes an imaginary scenario in which a baker living before the invention of money wanted a butcher’s meat but had nothing the butcher wanted.“No exchange can, in this case, be made between them,” Smith wrote.
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.
“Economic theory has always got to be historically bounded,” Beggs says. “I think it’s a mistake to think you’ll find the workings of modern money by going back to the origins of money.” He does point out that, while barter may not have been widespread, it’s possible that it happened somewhere and led to money, just given how much is unknown about such a large period of time.

In Canada, barter continues to thrive. The largest b2b barter exchange is Tradebank, founded in 1987. P2P bartering has seen a renaissance in major Canadian cities through Bunz - built as a network of Facebook groups that went on to become a stand-alone bartering based app in January 2016. Within the first year, Bunz accumulated over 75,000 users[29] in over 200 cities worldwide.

It is estimated that over 450,000 businesses in the United States were involved in barter exchange activities in 2010. There are approximately 400 commercial and corporate barter companies serving all parts of the world. There are many opportunities for entrepreneurs to start a barter exchange. Several major cities in the U.S. and Canada do not currently have a local barter exchange. There are two industry groups in the United States, the National Association of Trade Exchanges (NATE) and the International Reciprocal Trade Association (IRTA). Both offer training and promote high ethical standards among their members. Moreover, each has created its own currency through which its member barter companies can trade. NATE's currency is the known as the BANC and IRTA's currency is called Universal Currency (UC).[28]
In trade, barter (derived from baretor[1]) is a system of exchange where participants in a transaction directly exchange goods or services for other goods or services without using a medium of exchange, such as money.[2] Economists distinguish barter from gift economies in many ways; barter, for example, features immediate reciprocal exchange, not delayed in time. Barter usually takes place on a bilateral basis, but may be multilateral (i.e., mediated through a trade exchange). In most developed countries, barter usually only exists parallel to monetary systems to a very limited extent. Market actors use barter as a replacement for money as the method of exchange in times of monetary crisis, such as when currency becomes unstable (e.g., hyperinflation or a deflationary spiral) or simply unavailable for conducting commerce.
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. 

Another advantage of bartering is that you do not have to part with material items. Instead, you can offer a service in exchange for an item. For instance, if your friend has a skateboard that you want and their bicycle needs work, if you are good at fixing things, you can offer to fix their bike in exchange for the skateboard. With bartering two parties can get something they want or need from each other without having to spend any money.
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.
Economic historian Karl Polanyi has argued that where barter is widespread, and cash supplies limited, barter is aided by the use of credit, brokerage, and money as a unit of account (i.e. used to price items). All of these strategies are found in ancient economies including Ptolemaic Egypt. They are also the basis for more recent barter exchange systems.[15]

Barter-based economies are one of the earliest, predating monetary systems and even recorded history. People can successfully use barter in many almost any field. Informally, people often participate in barter and other reciprocal systems without really ever thinking about it as such -- for example, providing web design or tech support for a farmer or baker and receiving vegetables or baked goods in return. Strictly Internet-based exchanges are common as well, for example exchanging content creation for research.
Barter, the direct exchange of goods or services—without an intervening medium of exchange or money—either according to established rates of exchange or by bargaining. It is considered the oldest form of commerce. Barter is common among traditional societies, particularly in those communities with some developed form of market. Goods may be bartered within a group as well as between groups, although gift exchange probably accounts for most intragroup trade, particularly in small and relatively simple societies. Where barter and gift exchange coexist, the simple barter of ordinary household items or food is distinguished from ceremonial exchange (such as a potlatch), which serves purposes other than purely economic ones.