The Accrual Method of Accounting
In order to comply with U.S. GAAP and IAS, however, companies must present their income statement on an accrual basis, reporting revenues when earned and expenses when incurred. The timing of when revenues are earned does not necessarily coincide with when cash is received. Likewise, the timing of when expenses are incurred does not always coincide with when the expenses are paid. Instead, the matching principle requires that revenues and their associated expenses are recognized at the same time.
When the recognition of revenue or expense differs from the cash flow timing, it results in an accrual. Common accruals include:
The Intelligent Investor: The Classic Text on Value Investing
Financial Statement Analysis: A Practitioner's Guide, 3rd Edition
Managing Investment Portfolios: A Dynamic Process (CFA Institute Investment Series)