This research investigates inertia in a financial services context, with particular focus on the reasons for consumers’ dissatisfaction and inert behaviour, and studies the customers’ complaining behaviours and past and future inertia. The study utilised a two part methodology, including both qualitative and quantitative research. Twenty indepth interviews provided the preliminary data required for developing a questionnaire which was subsequently completed by 410 respondents. Determinants of dissatisfaction included the number and size of account fees, whilst determinants of inertia were the perception of similarity between financial institutions and the complexity, costs and time inherent in switching. Factors differentiating future inertia and future active customers included the type of account, length of time the account had been held, membership of a number of financial institutions, income and level of consideration giving given to changing financial institution.