The Department of Trade and Industry introduced the General Export Incentive Scheme in 1990 to encourage exports. Although introduced as a state prerogative, the scheme had the force of legislation and bound both exporters and officials. Participating exporters were required to submit claims for export incentives in a prescribed form and within prescribed time limits. The appellant, a clothing and lingerie manufacturer and exporter, participated in the scheme from 1990 and initially selected a six‑month claim period, which it consistently reflected in its claims until June 1994. For the period July 1994 to June 1995, the appellant submitted a claim in September 1995 and, for the first time, indicated a twelve‑month claim period. The Department refused to pay the portion of the claim relating to the first six months of that period on the basis that it was submitted out of time under the applicable guidelines. The appellant sought review of the refusal in the High Court, which dismissed the application, and then appealed to the Supreme Court of Appeal.