Broadly all corporation tax returns (including form CT600, supplementary schedules, tax computations and company accounts) in relation to accounting periods ending after 31 March 2010 and submitted after 31 March 2011, must be filed online as paper returns will no longer be accepted. In addition, corporation tax and related payments must be paid electronically.

Compulsory online filing will not change: - Who has to file a company tax return - When the return has to be filed or the tax paid - What is legally required to be filed as part of a company tax return However, what will change is the format in which the returns and accompanying computations and documents will have to be filed. Specifically CT600 returns will have to be submitted online in XML (Extensible Markup Language) format together with the accounts and tax computations in iXBRL (Inline eXtensible Business Reporting Language) format. The iBXRL format is a development of web page HTML which allows a document to be read in human-readable form but also allows the information in the same document to be read by computer software. We will work with you to comply with the new obligations but please contact us if you want any further information.