A tax accounting period for Corporation Tax purposes cannot exceed a 12 month period. If company accounts cover less than 12 months then the accounting period will normally end on the same day, and thus will be shorter than 12 months. This can happen if the company stops trading or shortens its company’s year-end: also known as its accounting reference date.

There is an interesting anomaly if the company has more than one trade. If this is the case, the company may make up accounts for one or more of them with different accounting dates, instead of one account for all its activities. In a case like this, the company should agree the accounting date it will use. Normally a date which achieves an unbroken succession of 12-month periods is preferable.

Companies may also have to contend with having two different company accounting periods. This is because there are different rules for Companies House filings and for HMRC to whom any Corporation Tax due is ultimately paid.