An increasing number of households in Northern Ireland has started to collect oil stamps in recent years - i.e. small pieces of paper which can be purchased at specified outlets, collected on an oil stamps savings card, and used to pay in full or part for one's oil bill. In this paper, we explore why this is. After ruling out high costs associated with more conventional savings vehicles (such as bank accounts) and the notion that oil stamps serve some purpose other than saving for heating oil as possible explanations, we test two main hypotheses: i) oil stamps as 'self-control' mechanism and ii) oil stamps as 'other-control' mechanism. While we find little evidence for the first hypothesis, we do find evidence for the second one. More specifically, we find that collecting oil stamps is strongly correlated with differences in views among household members with regard to how much priority to give to saving for heating oil. To rule out 'salience effects' as an alternative explanation, we test whether oil stamps increase households' savings performance. We find that they do.