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HMRC internal manual

Company Taxation Manual

HM Revenue & Customs
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Corporation Tax self-assessment (CTSA): Discovery determination: General

FA98/SCH18/PARA41 (2)

A discovery determination is the counterpart of a discovery assessment.

You make a discovery assessment when a discovery relates to:

  • understated profits, or
  • overclaimed or overstated relief,

that leads to additional tax liability for the company for the period to which the discovery relates - see CTM95030 onwards.

You make a discovery determination when a discovery:

  • relates to
    • overstated losses, or
    • overclaimed or overstated relief, and
  • leads (or may lead) to additional tax liability either:
    • for a different period from that to which the discovery relates, or
    • for a different company.

Despite the use of the word “determination”, a discovery determination under Paragraph 41 (2) is totally different from a “Revenue determination” under FA98/SCH18/PARA36 or 37.

You can only make a Revenue determination under Paragraphs 36 and 37 when:

  • the company has not delivered a return, or
  • it only partly complies with a notice to deliver a return.

You can only make a discovery determination when:

  • the company has already delivered a return.