An interim audit involves preliminary audit work that is conducted prior to the fiscal year-end of a client. The interim audit tasks are conducted in order to compress the period needed to complete the final audit. Doing so benefits the client, which can issue its audited financial statements sooner. An interim audit also helps the auditors, who now have more time available during their peak audit season to engage in activities for more clients.
An interim audit can also refer to a full audit that is conducted for an interim period, such as for a quarter or half-year. This is a relatively uncommon event, since publicly held companies only need to have a review conducted at quarterly intervals, not a full audit.