Accounting software is computer software that records and processes accounting transactions within functional modules such as accounts payable, accounts receivable, payroll and trial balance. It functions as an accounting information system. It may be developed in-house by the company or organization using it, may be purchased from a third party, or may be a combination of a third-party application software package with local modifications. It varies greatly in its complexity and cost.

Since the mid 1990s, the market has been undergoing considerable consolidation, with many suppliers ceasing to trade or being bought by larger groups, notably by Sage and Microsoft.