This paper is an attempt to empirically test a theory of access that investigates the logic behind the apparent ad hoc lobbying behavior of business interests in the European Parliament. The theoretical framework tries to explain the degree of access of different organizational forms of business interest representation (companies, associations and consultants) to the European Parliament in terms of a theory of the supply and demand of "access goods". The generated hypotheses are analyzed in an empirical study of the EU financial services sector. On the basis of 14 exploratory and 27 semi-structured interviews the hypotheses are checked in the Committee on Economic and Monetary Affairs of the European Parliament.