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HMRC internal manual

Company Taxation Manual

HM Revenue & Customs
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Corporation Tax: computation of income: broad principles


The Tax Law Rewrite project marked a major change of principle underlying the corporation tax charge on income, but without changing the calculation. Corporation Tax Act 2009 and Corporation Tax Act 2010 contain their own rules in place of the approach which computed income for CT purposes in accordance with IT principles, subject to exceptions. This change recognised that these exceptions, for instance those governing loan relationships, were now of major importance. CTM02020 explains the old approach based on IT law. CTM02030 gives more detail on the replacement Acts.

The Corporation Tax Acts

ICTA88/S831 (1) contains a definition of the Corporation Tax Acts in terms of the Acts relating to the income and chargeable gains of companies, and of company distributions, including provisions relating also to income tax. This definition applies within ICTA88, but there is a definition on similar lines within Schedule 1 to the Interpretation Act 1978 which applies generally. The provisions for chargeable gains continue to be found mainly in TCGA92 - see TCGA92/S8. Thus, the phrase does not just mean CTA09 and CTA10.