Income that is received in a fund or by company by providing a service or selling a product, but still has to be received. Mutual funds or other pooled assets that build up income over a period of time but only reimburse it out to shareholders once a year are, by meaning, accruing their income. Individual corporations can also accrue income without really getting it, which is the base of the accrual accounting system.
For instance, suppose that a company is projected to complete services for another corporation once per month for six successive months, but that in the terms of the contract, it will not be given monetary payment for these services until the finish of the six-month period. The company doing the services can accrue a percentage of the income gained after every month, even though physical payment will not occur until after the six-month period.