Mutual credit
Mutual credit is a type of alternative currency in which the currency used in a transaction can be created at the time of the transaction. Local exchange trading systems (LETS) are mutual credit systems. Typically this involves keeping track of each individual's credit or debit balance. Although the effect is like a loan, no interest is charged, and since mutual credit allows for trading and cancelling balances with others, debts can be paid off indirectly. The "IOU" is a common example of this.