The accounting reference date is the date to which a company makes up its accounts each year (i.e. the final day of the accounting year).
When a company is formed, the Registrar will allocate an accounting reference date, which will be the last day of the month in which the company was incorporated. The accounting reference date can be changed at any time by a resolution of the board of directors and filing Form 225 with the Registrar of Companies.
However an accounting period cannot be extended to more than 18 months, and unless specific criteria are met, an accounting reference date cannot be changed more than once in any 5 year period.