The use of computers in the processing of financial information by the client affects the general approach of the auditor to his work. The use of computers does not affect the auditor’s primary responsibility of reporting on the accounts but the way in which the auditor carries out his substantive and compliance procedures to arrive, at his opinion will be considerably different.


When planning for an audit in a computerised system the following factors must be considered:

  • Auditors need to be involved in computerised systems at a planning, development and implementation stages. Knowledge of the systems gained at these stages will enable the auditor to plan the audit with an understanding of the system.
  • Timing is more important in computerised environments than in manual environment because of the need of the auditor to be present when data and the files are available, more frequent visits to the client are usually required.
  • Recording methods may be different. Recent developments including; the use of portable laptops to aid in preparing audit working papers or coupling a client’s mainframe computer to a micro computer in the auditor’s office enabling auditors to download data files onto their own personal computers.
  • The allocation of suitably skilled staff to the audit. Thus audit firms now use the computer audit department on some parts of the audit and allowing general audit staff to have some computer experience.
  • The extent to which computer assisted audit techniques can be used. These techniques often require considerable planning in advance.


The auditor tests internal controls when he wishes to place reliance on the controls in determining whether the accounting records are reliable.A computerised system may differ from a manual system by having both manual and programmed controls. The manual controls are tested in exactly the same way as in a manual system.

The programmed controls are tested in the following ways:

  • By examination of exception reports and rejection reports. But there is no assurance that the items on the exception reports were the only exceptions or that they actually met the parameters setby management, auditors must seek for ways to test the performance of the programs by auditing through the computer.
  • Use of CAAT’S - Computer Assisted Audit Technique’s

Test data is mainly applied in testing computerised information systems.