One of the arguments for privatization is to promote market competition in order to facilitate efficiency gains. This review of NAO privatization reports shows that the promotion of competition is rarely stated as an objective of a privatization and, where it is, it can lead to difficulties in drawing objective audit conclusions. The work of the regulators is of considerable importance after privatization; and a more recent role for the NAO is that of responsibility for the financial audit and value-for-money studies of these regulators. These NAO studies provide new opportunities to review the effectiveness of the regulators and to promote accountability in competition policy after privatization.