SSAP 17 gives guidance on the identification and treatment of two types of post balance sheet events: adjusting and non-adjusting. For the purposes of the standard, post balance sheet events are defined as those that occur between the balance sheet date and the date on which the financial statements are approved by the board of directors.

The standard distinguishes between two different types of post balance sheet events. Adjusting events are those post balance sheet events which provide additional evidence of conditions existing at the balance sheet date. Non-adjusting events are those post balance sheet events which concern conditions that did not exist at the balance sheet date.

Events arising after the balance sheet date need to be reflected in financial statements if they provide additional evidence of conditions that existed at the balance sheet date and materially affect the amounts to be included.

To prevent financial statements from being misleading, disclosure needs to be made by way of notes of other material events arising after the balance sheet date which provide evidence of conditions not existing at the balance sheet date. Disclosure is required where this information is necessary for a proper understanding of the financial position.

SSAP 17 is effective for accounting periods starting on or after 1 September 1980.  It is being superseded by FRS 21 (IAS 10), which is effective for accounting periods starting on or after 1 January 2005.