HMRC has issued a reminder on the changes to corporation tax which will require all company tax returns sent in from April 2011 to be filed online, for accounting periods ending after 31 March 2010, in a specified data format (known as Inline XBRL or iXBRL). CT payments must also be made electronically from April 2011.

As well as limited companies, the changes will affect other organisations that pay corporation tax, including clubs, societies, associations, co-operatives, charities and other unincorporated bodies.

Companies will be able to file online either through commercially available software or by using HMRC's own CT filing software, which is aimed at companies with less complex tax affairs.

Further information on these changes and on the new joint filing service is available on here.