Internal Control: Guidance for Directors on the Combined Code (1999) also known as the "Turnbull Report" was a report drawn up with the London Stock Exchange for listed companies. The committee which wrote the report was chaired by Nigel Turnbull of The Rank Group plc. The report informed directors of their obligations under the Combined Code with regard to keeping good "internal controls" in their companies, or having good audits and checks to ensure the quality of financial reporting and catch any fraud before it becomes a problem.

Revised guidance was issued in 2005. The report was superseded by a further FRC guidance issued in September 2014.