Prior to 1963, the examination boards had a system for the grading of results at A Level which they had worked out in conjunction with local education authorities to assist the latter in selecting candidates for their university awards. This system, which applied four grades, was not officially recognised, and the grades were not entered on candidates’ certificates. In 1963, following acceptance of recommendations in the Third Report of the Secondary School Examinations Council (SSEC), an official system of five grades of pass designated A, B, C, D, and E was adopted.

The new system was criticised: concerns were expressed at the narrow band of marks which sometimes spanned two or three grades, the absence of any estimate of the reliability of the marks (there were no schemes of comparability between examination boards), and the consequent possible injustices to candidates which may have arisen from this in the competition for university places. In 1969 the Schools Council was asked to review the system of A Level grades in the light of this criticism.

Proposals for a new system of grading A Level results, which included using a numerical scale from 1 to 20 where 1 represented the highest level of performance, were circulated by the Schools Council to schools and universities for comment in 1970. However, strong opposition to the proposals from some GCE Boards and other interested bodies convinced the Secretary of State for Education and Science that the existing grading system was not so unsatisfactory as to require total replacement by the School Council’s proposed scheme.

In 1984 the Secondary Examinations Council (SEC), prompted by the publication of 'Problems of the GCE Advanced level grading scheme' by the Joint Matriculations Board (JMB), established an A Level Working Party to consider the problems inherent in the current system of A Level grading with particular reference to the narrowness of the grade C band. The outcome was the publication by the Department of Education & Science (DES) in March 1986 of a new grading system, which took effect in the 1987 summer examinations. The five A Level pass grades A to E were retained. But the “allowed Ordinary level pass” grade was replaced by an N grade (denoting a narrow failure) and an unclassified performance was identified by U.