This chapter outline three pragmatic approaches for measuring and attributing voluntary compliance outcomes. These voluntary compliance outcomes relate to taxpayers’ behaviour in complying voluntarily with tax obligations: registration, filing, reporting, payment and any additional obligations. In essence, it is about taxpayers being “in control” of their tax obligations, which covers both what tax results and how the taxpayer got to that result. These approaches are not exhaustive but draw attention to some of the best current and emerging practice for revenue bodies to consider drawn from a survey of the OECD Forum on Tax Administration membership.