A year of account of a syndicate which has not been closed by reinsurance to close.
There are two types of open year of account; naturally open years of account and run-off accounts.
Syndicates are required to keep each year of account open for a minimum of three years before it may be closed by reinsurance to close. In normal circumstances a syndicate will therefore have three naturally open years of account at any point in time: the third year of one year of account, the second year of the following year of account; and the first year of the next year of account. Thus in 2005 the 2003 year of account is in its third year, the 2004 year of account is in its second year and the 2005 year of account is in its first year.
Where the liabilities attaching to a particular year of account of a syndicate (including any prior year of account closed into that year) cannot be quantified after three years then that year of account will be left open until such time as a reinsurance to close may be effected or all the liabilities attaching to that year of account are extinguished.