Disclaimer of opinion
In one sentenceA case in which the auditor gives no opinion at all because sufficient evidence could not be obtained, and the possible effect may be material and pervasive.
Simply put
In a disclaimer, the auditor says neither that the statements are sound nor that they are wrong: the auditor says a judgment cannot be made.
Its most common causes are missing records and documents, or the auditor being prevented from seeing key matters.
Example
A business lost most of its documents for a whole year after a hardware failure with no backup, so the auditor found nothing to verify the balances with and disclaimed an opinion.