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HMRC internal manual

Company Taxation Manual

CTSA: introduction: computer system

A computer system called the Company Tax System or COTAX supports CTSA.


  • continues the support previously provided by the CTPF system for CTPF accounting periods,
  • provides equivalent support for CTSA,
  • has a built-in system of Help, Instructions and Training (HINT), which includes an On- line Company Tax Manual (COM)
  • like the other Revenue national systems, is managed by the Department in partnership with EDS.

If an office that does not have access to COTAX needs such access it should raise thematter, in the first instance, with the CT help desk (This content has been withheld because of exemptions in the Freedom of Information Act 2000) .