All company tax returns filed on or after 1 April 2011 that relate to accounting periods ending on or after 31 March 2010 must be filed in a specified data format known as inline extensible business reporting language (iXBRL). From the same date, all payments of corporation tax must be made electronically.
HMRC has issued an urgent alert to agents and businesses reminding them of the forthcoming changes. The alert can be viewed on the HMRC website.