When barter has appeared, it wasn’t as part of a purely barter economy, and money didn’t emerge from it—rather, it emerged from money. After Rome fell, for instance, Europeans used barter as a substitute for the Roman currency people had gotten used to. “In most of the cases we know about, [barter] takes place between people who are familiar with the use of money, but for one reason or another, don’t have a lot of it around,” explains David Graeber, an anthropology professor at the London School of Economics.

In Spain (particularly the Catalonia region) there is a growing number of exchange markets.[20] These barter markets or swap meets work without money. Participants bring things they do not need and exchange them for the unwanted goods of another participant. Swapping among three parties often helps satisfy tastes when trying to get around the rule that money is not allowed.[21]

Her answer came, finally, in an unlikely place: at a bar on Robson Street in Vancouver during the Winter Olympics. It was close to midnight, and she was waiting in line for a drink. All around her, people were partying—except for the two women in front of her, who were dissecting the differences between tax-free savings accounts and RRSPs. Simmons barged in to their conversation. “What do you want to know about TFSAs?” she asked. “What’s your goal?” She pulled the two aside and, for 20 minutes, gave an impromptu finance session. As a gesture of thanks, the two women bought Simmons and her group a round of beer. “I can’t afford financial advice,” one of them told Simmons, “but at least I can give everybody here a beer.” Then, Simmons felt like a cartoon megawatt bulb appeared over her head. It is all you can do, she thought. It is all you can do. There, in the middle of the crowded bar, she blurted, “Oh my god! I’m bringing barter back!”

Bartering allows individuals to trade items that they already have but are not using for items that they need while keeping their cash on hand for expenses that cannot be paid through bartering such as a mortgage, medical bills and utilities. Bartering can also have a psychological benefit because it can create a deeper personal relationship between trading partners than a typical monetized transaction. Bartering can also help people build professional networks and market their businesses.
Corporate barter focuses on larger transactions, which is different from a traditional, retail oriented barter exchange. Corporate barter exchanges typically use media and advertising as leverage for their larger transactions. It entails the use of a currency unit called a "trade-credit". The trade-credit must not only be known and guaranteed, but also be valued in an amount the media and advertising could have been purchased for had the "client" bought it themselves (contract to eliminate ambiguity and risk).[citation needed]
When exchanging services, it’s important to remember that bartering is considered income. While you may be able to write off expenses you incur during the barter, you must claim the fair market value of the services you provided as income. For example, if you charge $60 an hour as a massage therapist, and you trade a one-hour massage for housecleaning services, you may have to claim the equivalent income. When you trade assets, you may even be responsible for tracking capital gains or losses. If you have any doubts or questions, consult the IRS website.
While one-to-one bartering is practiced between individuals and businesses on an informal basis, organized barter exchanges have developed to conduct third party bartering which helps overcome some of the limitations of barter. A barter exchange operates as a broker and bank in which each participating member has an account that is debited when purchases are made, and credited when sales are made.
During economic downturns, when there is a keenly felt shortage of jobs and cash, people have historically adopted barter systems. The world’s most established bartering-style system is Switzerland’s wir: the German word for “we” as well as the abbreviation of Wirtschaftsring, which translates loosely to “economic circle.” In 1934, the economy in Switzerland had tanked—as it had in much of the world. Two businessmen who were facing bankruptcy, Paul Enz and Werner Zimmermann, gathered 15 of their associates in Zurich and hashed out a solution: a mutual credit system.