Ad hoc accounting is done for a specific purpose without considering any other issues. Ad hoc comes from the Latin and means "as the occasion requires."
The ad hoc principle applies to many dimensions in business. There may be an ad hoc committee formed to consider a specific issue, often of an urgent nature. Ad hoc accounting and reporting means that the accounting activity or report is produced to answer a single, specific question without prior planning or notice. Ad hoc analysis often comes in the form of a report or data summary. It is sometimes used to get current data rather than using a static report which may be dated.