1.The year to which a risk is allocated and to which all premiums and claims in respect of that risk are attributed. The year of account of a risk is determined by the calendar year in which it is first signed. A year of account is normally closed by reinsurance to close at the end of 36 months. The system will come to an end when GAAP accounting takes over. 2. In reinsurance it is a method of accounting to a proportional treaty whereby all premiums and losses accounted during the year in question are accounted to that year regardless of the year of origin of the cession or of the date of loss. Contracts accounted on this basis are usually closed at the end of each year by a port folio transfer into the following year.
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The year in which an insurance or reinsurance contract that is underwritten by a syndicate is allocated for accounting purposes and into which all premiums and claims arising in respect of that contract are payable. Insurance or reinsurance contracts are generally allocated to years of account according to the calendar year of their inception date so that a contract that commences in 2005 will normally be allocated to the 2005 year of account. Historically syndicates have operated a three year accounting system which means that each calendar is normally left open for two further years before a profit or loss is determined. A year of account is normally closed by reinsurance to close at the end of 36 months. Compare open year of account and run-off account.
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The calendar year in which the original risk attaches.

Accounting system under which the insurer allocates all premiums to the relevant treaty year according to the dates they are due, while all losses are entered according to the date of the occurrence.