What are the factors which influence the reliability of audit evidence?

Following factors affects the reliability of audit evidence:

 The reliability of audit evidence is increased when it is obtained from independent sources outside the entity.

 The reliability of audit evidence that is generated internally is increased when the related controls, including those over its preparation and maintenance, imposed by the entity are effective.

 Audit evidence obtained directly by the auditor (for example, observation of the application of a control) is more reliable than audit evidence obtained indirectly or by inference (for example, inquiry about

the application of a control).

 Audit evidence in documentary form, whether paper, electronic, or other medium, is more reliable than evidence obtained orally.

 Audit evidence provided by original documents is more reliable than audit evidence provided by photocopies or facsimiles.

The auditor should obtain sufficient appropriate audit evidence to be able to draw reasonable conclusions on which to base the audit opinion.Audit evidence is obtained from an appropriate mix of tests of control and substantive procedures.

In some circumstances, evidence may be obtained entirely from substantive procedures.

The reliability of audit evidence is influenced by its source: internal or external, and by its nature: visual, documentary or oral. While the reliability of audit evidence is dependent on individual circumstance,

the following generalizations will help in assessing the reliability of audit evidence:

Audit evidence from external sources (for example, confirmation received from a third party) is more reliable than that generated internally.Audit evidence generated internally is more reliable when the related accounting and internal control systems are effective.Audit evidence obtained directly by the auditor is more reliable than that obtained from the entity.Audit evidence in the form of documents and written representations is more reliable than oral representations.

some practical insights about reliability of audit evidence other than generalization stated in iSA 500

1) Reliability of audit evidence increase when the corroborated evidence also assured the same results

2) Evidence generated by substantive procedures are more reliable.