Michael Linton originated the term "local exchange trading system" (LETS) in 1983 and for a time ran the Comox Valley LETSystems in Courtenay, British Columbia. LETS networks use interest-free local credit so direct swaps do not need to be made. For instance, a member may earn credit by doing childcare for one person and spend it later on carpentry with another person in the same network. In LETS, unlike other local currencies, no scrip is issued, but rather transactions are recorded in a central location open to all members. As credit is issued by the network members, for the benefit of the members themselves, LETS are considered mutual credit systems.
In the United States, Karl Hess used bartering to make it harder for the IRS to seize his wages and as a form of tax resistance. Hess explained how he turned to barter in an op-ed for The New York Times in 1975. However the IRS now requires barter exchanges to be reported as per the Tax Equity and Fiscal Responsibility Act of 1982. Barter exchanges are considered taxable revenue by the IRS and must be reported on a 1099-B form. According to the IRS, "The fair market value of goods and services exchanged must be included in the income of both parties."
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.
As Orlove noted, barter may occur in commercial economies, usually during periods of monetary crisis. During such a crisis, currency may be in short supply, or highly devalued through hyperinflation. In such cases, money ceases to be the universal medium of exchange or standard of value. Money may be in such short supply that it becomes an item of barter itself rather than the means of exchange. Barter may also occur when people cannot afford to keep money (as when hyperinflation quickly devalues it).
Make the deal. After you've found a barter partner, get the agreement in writing. Make sure you detail what services or goods will be involved, the date of the exchange (or work to be done) and any recourse if either party reneges on their part of the deal. If you are working through a membership-based bartering association, they will likely provide all the structure and paperwork you need for the deal.
For instance, each time Apple releases a new version of the iPhone, the second-hand market for older versions of the iPhone enjoys a flurry of activity. However, you do have to be as careful with the barter of used goods as you would be with the purchase of used goods. Be sure everything is in working order and shows no signs of significant damage.